I think I answered this somewhere else on the forums, but I'm happy to reiterate again for newer people such as yourself.
Custom vehicles and other custom things are the main parts of keeping the server funded which has enabled us for the past 5 years to provide a free to play experience with 0 pay to win advantages whatsoever. It's also what allows us to consistently pump out new content. Unfortunately there is not another way that doesn't involve compromising the integrity of gameplay, for example perma weapons. Nothing you can donate for gives you an inherent advantage over people who don't donate. Before we introduced custom cosmetics and things that solely make an impact visually, there were many months were the server did not make enough to sustain itself, let alone allow for consistent new content. It's a small compromise, and one that is needed to allow the server to exist and improve constantly. Out of year vehicles are intentionally priced higher to dissuade people from obtaining them. Meaning there are way fewer in existence.
Also, we actively deny many absurd requests and will continue to do so. Not everything can run free.
Hope that explains it! We do our best to keep everything as accurate as possible, but for us to continue providing the experience that sees hundreds of unique players connecting a day providing thousands of hours of entertainment without any real requirement to pay out, it's something that must be done. Unlike many other servers myself and the staff team do this out of passion, we're not here to make a quick buck - but we have to be realistic about things, especially something we pour a lot of our free time into.