SEver since my childhood, I've been fond of cars. Ever since my childhood, I've been fond of cars.

Since my childhood, I've been fond of cars. Since my childhood, I've been fond of cars.

Since my childhood, I've been fond of cars. Since my childhood, I've been fond of cars.

Since childhood, I've been fond of cars- 'I have been' expresses a continous action originating in the past using the verb 'to be'. verbs such as this show actions that happened in the past and continue to present time

My family says that I used to find thelook for car advertisements in newspapers to see the cars. My family says that I used to look for car advertisements in newspapers to see the cars.

Look for / search = the act of trying to find something

My family says that I used to find the car advertisements in newspapers to see the cars. My family says that I used to find the car advertisements in newspapers to see the cars.

Perfect. good job!

My favourite car brand in my childhood was Audi. My favourite car brand in my childhood was Audi.

My favourite car brand in my childhood was Audi. My favourite car brand in my childhood was Audi.

Just for information, we often use the word "make" specifically for car manufacturers. An alternative for your sentence would be, "My favourite make of car during my childhood was Audi." We would use "model" for the specific car from that manufacturer. E.g., "the make and model of my car is a Volkswagen Polo."

My favourite car brand in childhood was the Audi. My favourite car brand in childhood was the Audi.

'when I was a child' or 'as a child' is more grammatically correct, was 'the' Audi. Putting a definite article highlights Audi it as a particular car brand.

Most of my toys includwere cars and bikes mostly. Most of my toys were cars and bikes.

Most of my toys included cars and bikes mostly. Most of my toys included cars and bikes.

No need to use the word "most" twice

Most of my toys include cars and bikes mostly. Most of my toys include cars and bikes.

Repetition of the same word. Add 's' to car to show plural form

My favourite cCar. My favourite Car.

Proper nouns are always capitalized

I used to cut out the Audi advertisement photos and keep ithem on my shelf. I used to cut out the Audi advertisement photos and keep them on my shelf.

I used to cut out the Audi advertisement photos and keep them in my shelf. I used to cut out the Audi advertisement photos and keep them in my shelf.

To physically remove it = cut out

I used to cut the Audi advertisement photos and keep them in my shelf. I used to cut the Audi advertisement photos and keep them in my shelf.

Reflex verbs helps us to indicate that things or peple are being -re-refferred to within a given sentence.

When I used to go to school and come back home I used towould come back home from school, I would sit at the window seat just to see the luxury cars. When I would come back home from school, I would sit at the window seat just to see the luxury cars.

When I used to go to school and come back home, I used to sit atin the window seat just(of the bus/car) just to be able to see the luxury cars. When I used to go to school and come back home, I used to sit in the window seat (of the bus/car) just to be able to see the luxury cars.

When I used to go to school and come back home, I used towould sit at the window seat just to see the luxury cars. When I used to go to school and come back home, I used would sit at the window seat just to see the luxury cars.

"would' is a better form of the words "used to" and help to avoid repetition

Nowadays I am not that muchas interested in the Audi brand that much because, now, as I know more other brands. Now I am not as interested in the Audi brand, as I know other brands.

Nowadays, I am not that much interested in Audi brand that much because, now I know morea lot of other brands. Nowadays, I am not much interested in Audi because now I know a lot of other brands.

No need to repeat "much" twice

Nowadays I am not that muchas interested in Audi brand that much because, now I know more about other brands or now I am aware of other brands. Nowadays I am not that as interested in Audi brand because, now I know more about other brands or now I am aware of other brands.

Avoid word repetition and we use 'know about' if we do not have non-personal knowledge and "know' when we have full knowledge of something or someone

But I have still kept my hHotw Wheels toy cars safely because ithey reminds me of my childhood. But I have still kept my Hot Wheels toy cars safe because they remind me of my childhood.

Hot Wheels is a name, so is capitalized

But I have still kept my hotwheels toy cars safely because ithey reminds me of my childhood. But I have still kept my hotwheels toy cars safely because they reminds me of my childhood.

We use a reflexive pronoun to indicate you are referring to the 'toys'.

To be honest, I still take a look at the current hHotw Wheels collections at shopping stores and malls. To be honest, I still take a look at current Hot Wheels collections in stores and malls.

To be honest, I still take a look at the current hHotw Wheels collection at shopping stores and malls. To be honest, I still take a look at the current Hot Wheels collection at shopping stores and malls.

Good job. Add a comma to express a thoughtful pause

I still find ithem very fascinating/interesting. I still find them very fascinating/interesting.

Just a comment, "fascinating" is VERY strong. If that's what you meant, great, but otherwise just "interesting" is more appropriate to say that you still enjoy looking at them.

I still find it very fascinating. I still find it very fascinating.

Excellent!