I never thought I cwould be able to afford a car in my lifetime as I was not rich, doing an ordinary job and earning only a little bit of money.

I changed "could" to "would be able to" because "could" here can imply that some lack of knowledge prevented you from realizing that you could in fact afford a car, whereas "would be able to" more clearly expresses that your past financial situation was what was stopping you.

It's an extremely subtle thing though - most English speakers would have no trouble understanding what you really meant.

When I was forty - two years old, I did something in my spare time and earned a certain amount of money, so I started to consider buying a car.

For "did something in my spare time (to earn money)", a very common way to say this is that you "did some work on the side", or "did a side gig."

However, tThe money I earned was not that much, only around one hundred thousand100,000 CNY, n. Not enough for a decent family car.

In English I usually see digits for large numbers, or any number if it is money.

I went to a local Volkswagen 4S store to see and experience it in person, andbut then I saw a black car near the Lavida, so I got in the black car and compared it with the Lavida.

I changed "and then" to "but then" since it provides more contrast. You were there to see the Lavida, but you ended up more interested in this mysterious black car.

It was spacious inside, refined in the manufacturing processhad great build quality, and looked more upscale.

Like the other commenter said, you can also say it was "well-made." I chose "build quality" since it is commonly associated with things that require complex manufacturing like cars, laptops, phones, etc.

The sellersalesmen in the store told me it was another model of Volkswagen called the Passat.

"Seller" is fine but "car salesman" is the most common way to describe someone who sells cars at a car dealership.

When referring to a specific car, the model name usually has an article before it (the/a). Example: "I drive a VW Passat," "The VW Passat passed us on the left."

I see some official documents drop the "the" but most people continue to include at least "the" when referring to the model line.

I immediately changed my idea ofmind about which model I would buy, but the lowest version of the Passat was the 2.0 MFI, around one hundred and sixty thousand160,000 CNY.

I got home and told my wife about what I had seen and felt in the car storedealership.

My wife told me we could borrow some money from her family if I really wanted to buy the goodnicer one.

Calling it "the good one" makes it sound like the other car is bad. "Better" or "nicer" or "more expensive" is more precise (unless you really think the Passat is a bad car).

Therefore,So we borrowed around fifty thousand CNY from her parents and her younger brother, and took the Passat home.

"Therefore" is usually used in statements that are logically linked. It isn't usually used when you are describing an action you took, unless you are speaking in very precise and formal terms.

"My family loaned me the money, so I bought the car."

"My family loaned me the money, therefore I felt comfortable buying the car." You bought the car for more reasons than just your family loaning you the money, but them loaning you the money is exactly what made you feel financially comfortable buying it.

I never thought I could afford a car in my lifetime asbecause I was not rich, doinghad an ordinary job, and earninged only a little bit of money.

"Because" is clearer than "as" for causal explanation. Using "had an ordinary job" fits better as past tense describing your situation. "Earning a little bit of money" was changed to "earned only a little money" for a more concise and formal tone.

When I was forty - -two years old, I did something in my spare time and earned a certain amount ofsome money, so I started to consider buying a car.

Removing spaces around the dash makes "forty-two" a proper compound number. "A certain amount of money" was changed to "some money" for a more natural and simple expression.

However, the money I earned was not that much, — only around one hundred thousand CNY, — which was not enough for a decent family car.

"Not that much" was changed to "not much" for conciseness. Using em dashes instead of commas better sets off the additional information, making the sentence clearer.

Based on the amount of the money, I washad, I planninged to buy a Volkswagen Lavida asbecause the money was just enough for it.

"The amount of the money" was clarified to "the amount of money I had" to specify whose money. "I was planning" was changed to "I planned" for a more direct narration. "As" was replaced by "because" for a clearer cause-effect relation.

I went to a local Volkswagen 4S store to see and experience it in person, and t. Then I saw a black car near the Lavida, so I got into the black car and compared it with the Lavida.

Splitting the long sentence into two improves readability. "Got in" was changed to "got into" because it is the more natural phrase when entering a vehicle.

It was spacious inside, refined in the manufacturing processwell-made, and looked more upscale.

"Refined in the manufacturing process" is wordy and unnatural, so "well-made" is a simpler and more natural phrase here.

The sellers in the storalespeople told me it was another model of Volkswagen model called the Passat.

"Sellers in the store" changed to "salespeople" for more natural wording.

I immediately changed my idea ofmind about which model I would buy, but the lowestbase version of the Passat was 2.0 MFI, costing around one hundred and sixty thousand CNY.

"Changed my idea of which model" was changed to "changed my mind about which model" for natural expression. "Lowest version" changed to "base version" which is common car terminology. Added "costing" for clarity.

I got home and told my wife about what I had seen and felt inat the car store.

Simplified "about what I had seen and felt" to "what I had seen and felt." "In the car store" changed to "at the car store," which is more natural.

My wifShe told me we could borrow some money from her family if I really wanted to buy the good onebetter car.

"The good one" was changed to "the better car" for clarity

Therefore, we borrowed around fifty thousand CNY from her parents and her younger brother and tookbought the Passat home.

"Her younger brother" shortened to "younger brother" as "her" is already clear. "Took the Passat home" changed to "bought the Passat" for more precise meaning.

A few years ago, it often had big or smallmajor or minor problems, so that we needewe had to sendtake it to repair shops.

"Big or small problems" changed to "major or minor problems" for more natural phrasing. "Needed to send it" changed to "had to take it" for clearer, more active phrasing.

MaybeAbout one or two years ago, my wife decided to give the car to her cousin.

"Maybe" changed to "About" for clearer time reference.

Now I know littledon’t know much about it.

"I know little about it" changed to "I don’t know much about it" for more natural phrasing.

I never thought I could afford a car in my lifetime as I was not rich, doing an ordinary job and earning only a little bit/just a small amount of money.

When I was forty - two-two (42) years old, I did something in my spare time and earned a certain amount of money, so I started to consider buying a car.

However, the money I earned was not that much, only around one hundred thousand CNY, — not enough for a decent family car.

Sometimes it's nice to switch the punctuation with a dash, for style.

I went to a local Volkswagen 4S store to see and experience it in person, and then I saw when I noticed a black car near the Lavida, so I got in the black carhopped in that and compared it with the Lavida.

yours already sounded okay, I just made it sound a little more natural and native

The sellersalespeople in the store told me it was another model of Volkswagen called Passat.

I immediately changed my idea of which model I would buy, but the lowest version of the Passat was the 2.0 MFI, which was around one hundred and sixty thousand CNY.

I got home and told my wife about what I had seen and felt inat the car store.dealership.

A few years ago, it often had big or small problems so that we needed to send it to repair shops.

I would say it like this; A few years ago it kept having all sorts of problems, so we had to take it in for work.

Maybe onea year or two years ago, my wife decided to give the car to her cousin.

When I was forty - two years old, I did something in my spare time and earned a certain amount of money, so I started to consider buying a car.

Usually with two-digit numbers, one would use numerals.

Based on theat amount of the money, I was planning to buy a Volkswagen Lavida as ithe money was just enough for it.

The sellersales people in the store told me it was another model of Volkswagen called Passat.

A few years ago, it often/ frequently had big or small problems so thaten, we needed to send it to repair shops.