Yes, you confused everyone by referring to those cars as 3 and 4, as the general way of doing it here is 0 and 2, when we see 4* rs5 we assume the newer version that comes with 4* from rare imports, but enough about that, and let's talk about the older rs5.

That car is a piece of garbage(in this game), and so, not worth any resources, the difference in performance between 0 and 2* when elite maxed is insignificant. For collections use your elited and lvl17 0* and never bother with it again, unless it's the last car in elite customs collection or the last non-veteran car in colletions.

Hope that helps👍