...Wow, that's actually quite the cool thing to hear about- probably I've been too much out of the modern console loop but I didn't expect that a GT game would have support for .svg formats since that's something you would definitely need a PC to either create or at least make sure you find.
But definitely explains how you could easily get to add custom logos in your liveries.
It does make me happy to see cool stuff like this done in GT- both because of how even cooler some cars can be wit hthe right paint job, and because its one of the few things I can appreciate from the game as a spectator [you know, haven't got my hands on a PS5 so far lol]