I particularly like Hubcap's, Venom's and Chop Shop's. Here are Budiansky's complete Omnibot bios (Downshift's is awesome):

Camshaft
Universe Bio

Autobot RX-7
Code Name: Camshaft
Function: Road Warrior

Profile:

Unlike all others who travel the highways of Earth, Camshaft has no fear of car accidents, and with good reason: his lightning-fast automated reflexes allow him to pulverize any vehicle that approaches within 4 inches of his metal frame. The arrogant confidence he has about his own safety often leads to reckless driving, a fact that Optimus Prime is not too happy about. Camshaft doesn't share his leader's concern about the lives of his adopted planet's native inhabitants. But there's no doubt in Optimus's mind that Camshaft's aggressive nature is a boon in battle against the Decepticons, and Optimus is reluctant to say anything to Camshaft that might change that.

Abilities:

In car mode, Camshaft's rear fenders can convert to powerful fists, each capable of 30 punches per minute, each punch having a force of 80,000 psi. His trunk rotates into a high-energy plasma beam projector with a range of 2 miles. The same weaponry is available to him in his robot mode.

Weaknesses:

Converting to an offensive mode while in the act of driving sometimes causes Camshaft to lose control of his driving. As it is unlikely that he will back off from any confrontation, he often finds himself overmatched by an opponent.

Tech-Specs Bio

Autobot Camshaft
Function: Road Warrior

"The road is no place for the weak"

Has no fear of car accidents—can pulverize any vehicle that approaches within 4 inches. Reckless driver due to arrogant self-confidence. Unconcerned with humans’ safety. Aggressive in battle car mode rear fenders convert to powerful fists capable of 30 punches per minute and trunk turns into high-energy plasma beam projector... same weapons in robot mode. Loses driving control when using weapons in car mode.

STR: 5
INT: 6
SPD: 7
END: 8
RNK: 5
CRG: 8
FRP: 8
SKl: 6

Downshift
Universe Bio

Autobot Celica
Code Name: Downshift
Function: Air Defense

Profile:

Nothing pleases Downshift... or so he thought. Back on Cybertron this battle-weary soldier had fought for so many millennia that he began to wonder whether it was worth it for him to continue. But once he came to Earth he found everything around him fresh and new and he delighted in all his optical sensors saw. He particularly enjoys the company of human children, or, as he likes to call them, mini-men and mini-women (although he has as much trouble telling them apart as his fellow Autobots). His sullenness about the Autobots' mission is often of concern to Optimus Prime, but he generally follows orders, however grudgingly, because deep down he knows this truth: the unending Autobot resistance is preferable to a rapid Decepticon victory.

Abilities:

In robot mode, Downshift carries twin ground-to-air rocket launchers on his shoulders. The rockets use magnetism to guide their path, limiting them to mostly iron and steel targets, such as Decepticons. The launchers can also be used while he's in his car mode, making Downshift a very effective covert warrier. In either mode, the rockets can travel up to 30 miles and pack the explosive equivalent of a half ton of TNT. He also wields a "rust rifle" which shoots a stream of powerful liquid oxidizing agents. A blast of this can seriously harm and debilitate a metallic foe.

Weaknesses:

Downshift' s weapons are mostly ineffective against non-ferrous materials, a fact that can be used to his disadvantage by an opponent. His soldierly instincts are often hampered by his sullen moods.

Tech-Specs Bio

Autobot Downshift
Function: Air-Defense

"If war is the only reason to live, then living isn't worth it."

Fought for so long on Cybertron he wondered whether to continue... nothing pleased him until arrival on Earth... here he delights in everything...all fresh and new to him...likes children...calls them mini-men and mini-women. Has magnetic-guided ground-to-air rocket launchers on shoulders in robot mode... also can be used in car mode...30 mile range... rust rifle weakens foes with stream of liquid oxidizing agents. Not effective versus non-ferrous foes.

STR: 5
INT: 7
END: 6
CRG: 6
SPD: 7
RNK: 6
FRP: 8
SKL: 9

Overdrive
Universe Bio

Autobot Ferrari
Code Name: Overdrive
Function: Flying Trooper

Profile:

Road-racing is Overdrive's passion: he considers it Earth's primary cultural advantage over his native Cybertron. But the thrill of merely racing is not enough for Overdrive--if necessary he’ll lift off from the ground and fly in order to win! Good sportsmanship isn't his strong suit. And that carries over to his battle tactics too. He has no interest in a fair fight with a Decepticon; he only wants to win. And he’ll do whatever he must to make sure he does.

Abilities:

Besides being able to travel up to 190 mph while in car mode. Overdrive can also sprout wings from his doors and fly. His flying range is 700 miles and he can reach speeds of up to 300 mph. He can convert a section of the front of his hood into twin high-powered machine guns that shoot 60 rounds per minute. In robot mode he also has use of his wings and machine guns, although he's considerably less adept at flying.

Weaknesses:

Although his ability to fly while in car mode can often be used to surprising advantage. Overdrive's overall maneuverability in the air is often inferior to other airborne opponents.

Tech-Specs Bio

Autobot Overdrive
Flying Trooper

"The race is not important; the finish line is."

Road-racing his passion--considers it Earth's main cultural advantage over Cybertron. Only cares about winning ... he'll fly to win a race, do whatever's necessary to win a fight. Goes 190 mph in car-mode...can sprout wings from doors and fly...range 700 miles ... speed 300 mph. Hood converts to twin hi-powered machine guns ... Same abilities in robot mode not as good a flier. Overall not as good a flyer as most flying opponents.

STR: 5
INT: 7
SPD: 8
END: 6
RNK: 5
CRG: 10
FRP: 7
SKL: 5