Help with adding cars without removing gta's cars

Im having some problems adding custom cars to my vehicle shop, is it neccessary that i overwrite another car? Can anyone tell me how to just add the cars without removing the GTA cars.

You can add a car, you just need to rename the .ydd and .ytd file by a new name and create a carcols.meta/ carvarations.meta and a vehicles.meta file for your new car

You can find some exemple online

If i use a caraddon from another mod, i will be able just to use the mods carcols.meta and vehicles.meta right? instead of creating it myself?

Yeah you basicly can, but personally I would recommand to use the one direcly from gta, I will explain better, sorry for my bad english tho, what I would do, I would check the “addon” I would like to implement on my server and from that car I would chose a gta car to use his handling/carvariations/vehicle.meta files using OpenIV and from there you just have to replace the car name by your new car’s name