@JohnFromGWN Originals are locked inside the vehicles.rpf. But don't worry I'll redownload everything back with some improvement in some vehicles.

It'll take time but I can allow myself to spend it.

@JohnFromGWN Here is the dlc.rpf where is my vehicles.rpf.
https://www.mediafire.com/file/bxx1a6prek1s0r5/dlc.rpf/file
It isn't necessary to help me if you don't have time, I'll find a solution anyway.
I already started redownloading all the cars (it takes time but I'll finish it one day).

Once again thank you for the help!!

@JohnFromGWN Yes it is, I wasn't aware that a vehicles.rpf above 4GB would make the file corrupted.

@JohnFromGWN I sent a message to OpenIV. I hope they can solve this problem as I didn't find any working solution on the internet.

I always find a solution when I mod GTAV. I have to admit that this is the toughest problem I ever had.
And it was caused by something really stupid compared to all the modding non-sense I've done before.

Once again thank you for your help, I'm sure I'll find a solution.

@JohnFromGWN The problem is that I can't import my files inside my original vehicles.rpf because my file is corrupted.
I tried many ways to import them in OpenIV (Extract - Save content/Export) and it only extracted the vehicles.rpf.
I tried to replace the vehicles.rpf from a working mod by the wanted one but it failed...

@JohnFromGWN I thank you for the help you brought me but it didn't work.
I made what you recommended me to do but it failed.
I also discovered that all files can be successfully defragmented except my vehicles.rpf. (the file that is corrupted)

@JohnFromGWN I do realize it but I knew someone would see my question.
I tried to defragment my vehicle.rpf but it doesn't defragment it despite the fact that I selected it.
It finishes the defragmentation by telling me "it's completed" but I'm still not able to open it.
The dlc.rpf is the only one that I can defragment.
I want to defragment the dlc.rpf.

@Reyser Thanks for your help Reyser!
How do I defragment my vehicle.rpf file?
It is 4.1 GB I think and I don't have any backup of it (my bad).
Do you have any solution?
Thank for your reading!