I've gotta agree. So you wrapped an HHR, an Element, or an Astro van. Congratulations...you look just like every other wrapped sled out there.
Buy something with some charectar, some class, some originality and make an impression. Seriously, think about it. You can go buy a new HHR for $18,000, wrap it and go on your way. Four years from now you can pull the wrap off and sell it for $9000.
Or...you can spend $10,000 on a 1950s model panel truck already hot rodded/restored with a new drive train and interior, wrap it, turn some heads, drive it 4 years and sell it for more than you paid for it.
Look for a unique vehicle that will serve your needs. You'd be shocked at the bizarre rides you can find on ebay if you just do a search for all cars in a time frame within your budget. I'm currently looking for a 1950s model station wagon (and apparently so are several other people)
Don't look at boring, mundane, straight off the lot if you're wanting a promotional vehicle. You want more to stand out than just stickers.