I’ve seen somewhere before that Redline is another Gundam-like but with cars instead of mechs

I have no idea why anyone would say this. Gundam is about socio-political issues relating to space colonization and the horrors of war. Redline is about doing whatever is coolest at every moment. I cannot think of a single thing Redline has in common with Gundam, other than that the characters spend a lot of time sitting in cool machines. Anyways, I loved that movie. Redline is what showed me that it’s possible for a movie to be excellent while having the most basic plot imaginable.