After more than a decade with six-cylinder engines, the M3 in its next iteration will move up to a V-8, just as the latest M5 has migrated from eight cylinders to ten. We expect the new, high-revving V-8 to displace 4.0 liters and to share its basic architecture with the M5's V-10. The last M3 made do with "only" 333 hp, but the new M3 should have more than 400 ponies on tap, giving the Audi RS4 something to worry about. The sequential-manual transmission may go from six speeds to seven, as in the M5 and the M6. Expect it in late 2007.