I picked up a Barbie Beach Ranger Jeep PowerWheels today for $3!
It's big. Almost Grave-Digger sized. It's the style where it's all plastic (no metal frame under, like the Wrangler has.)
The plastic body is mostly two large pieces that connect together down a center line, which I think is exactly how Grave-Digger was designed.
I'm thinking about keeping this one to convert for Power Wheels Racing. It's big enough for my butt, and I think can fit one battery in front and one in back.
I have two photos at the links.
PS: It also has a working toy radio, with a siren, upbeat music, and Barbie saying "It's a great day for a cruise!". The small girl pressing the buttons OVER and OVER and OVER is starting to drive me crazy!