I know exactly the feeling - until I picked up my new E90 - its a whole lot better, more intelligent motor vehicle then my previous E46.
It's simply a matter of recalibrating your mind and getting over the old car.
Everytime, I pass an E46 I think to myself `Good old car' but feel quite smug in my E90 `Good new car'.
Soul searching over motor cars is a waste of good sleeping time.
Regards :