I'm no vehicle expert, but I would guess a Jeep Wrangler would be larger than a Viper and an Impreza. They sit up pretty high and aren't as streamlined, so that makes it look larger too. Scale looks right to me, but as I said, I'm no expert. *I'm hinting for David H. to chime in here. *
Here's some interesting news, I emailed the guy that runs Reprolabels.com and asked if he'd considered making larger scale G1 stickers for Hound since he's currently doing micro sized stickers for the WST figures. He emailed me back this:
"Hi! Not a bad idea at all Maybe when this toy shows up here in Canada I'll pick one up to work on that. Thanks!"
Hope he does it, with some modifications I think G1 Hounds stickers would look nice on BT-04.
It'll end up looking like the ltd. edition "Willys".
http://www.jeep.com/willys/index.html
Kinda goofy looking if you ask me.