Kickback. Of all the Insecticons, Kickback is my favorite, but next to the lightning-throwing Shrapnel and mind-controlling Bombshell, Kickback is always relegated to "the other guy."
His bio describes him as charming and manipulative, but he's always given the same personality as Shrapnel. I'd fix that by making him more the outspoken frontman of the group. Bombshell may be the schemer but Kickback will take you aside, flatter you, and explain how everything will work out. Kind of a cool guy that everybody sees as a friend, until right before you take a slug in the spark chamber for him and realize you were being played.
I see him as more of a leather jacket gangster than a Used Car salesman like Swindle, but I could definitely see the two of them working together/betraying each other.
His bio also talks about how he's good at kicking and jumping, which is lame as shit compared to mind control and lightning powers. I'd take that farther and give him Negasonic Teenage Warhead/Speedball's power: a kinetic field he can use to cannonball himself around and crash into people, or absorb impacts.