Welcome, Vince. I suspect you already know the answer... that bit about the warranty is the rub. Just keep reminding yourself that (1) performance is more than just acceleration -- enjoy the excellent handling, and (2) that 320i is easier on on the wallet that the more powerful models, too.
Originally Posted by vinni323
is there any way of upgrading the 320i to a potential 325i (in theory) while keeping my warranty.
BMW CCA #115780