So you downloaded the original .rpf and installed it right into FiveM without any changes? You just have to tell us how you did that. We would all love to hear about how it’s done.
Then you did make changes to the original download just as was done by OP. The op offered that resource just as you have chosen not to do with your 300 vehicles. Feel free not to download it but at the same time, also feel free to allow others to download a packaged fivem resource of the vehicle.
it still does not seem like converting. its basicly get the template. get open iv. open the car/truck in open iv. then move all the files to the right places in the template.