Is it true that BMW limited the performance of the M3 to egual that of the M5 but it actually can outperform the M5 and that Dinan makes a chip for the new M3 that takes away these factory limitations? This is what I heard from a dealership.

The engine produces over 100 hp/liter. I don't imagine there's much you can do to get significantly more power aside from punching it out or going forced induction. - Beau

DINAN dont have anything out at the moment for the M3.