"Sinister Four."

Considering how long it took to get three members of the Doom Patrol, it's impressive that we've got most of the Superior Foes of Spider-Man, considering their comic was cancelled over a year ago. (I do wish I had the old Shocker.) Right now we're short Overdrive, but he's a bit of a long shot: he's a relatively new villain, and somewhat nondescript. His Wikipedia entry even calls him "something of a throwaway joke character." Overdrive usually appears in a helmet and racing gear, and somewhat resembles an evil(er) version of Top Gear's the Stig. That may or may not be intentional; since Overdrive's powers are to transform any vehicle he's in to a super-powered one.

I don't remember much of Overdrive in the issues of Superior Foes that I've read, but I'm pretty sure he's the nicest one of the lot. In fact, Overdrive's career plan was to have a brief life of crime, then reform so he could join the Avengers. Hey, it worked for Hawkeye. And the Black Widow. And Quicksilver and the Scarlet Witch. And several others...it's not as bad a plan as I had thought, really.