I've said it before, but one character I'd really love is F-Type, from Stunt Race FX. He's the red vehicle, seen below:
I'm not sure how he'd hold items, but picture how cool it'd look seeing him trundle along, expanding and contracting cartoonishly, spewing fire from his tailpipe or dropping oil slicks or flashing his headlamp "eyes" to dazzle opponents. And of course when he hydraulically jumps into the air, he can tumble to and fro, "tricking" through the sky. I picture him popping his hood or tilting his spoiler to launch enemies, swinging open wing-like doors, and dashing along with the same joyful "thrum" as Wario's motorcycle.
Ahhh, it'd be so cool!