you could always do what me and my buddy did..
1. "aquire" two fast food trays ... (i prefer taco bell, cuz then i can mow on some delicious amer-exican grub)
2. find two cookie sheets that are roughly the same size
3. using a bit of jb weld (had some sitting around) glue a tray into each cookie sheet..
total cost.. maybe $6 (cookie sheets from goodwill) and we slid on those things for a good hour.
if you can find an asphalt parking lot, they will last longer. the rough surface of a normally paved lot eats them up faster.
but then i got my supra and have discovered the joy of not needing pans to get my car sideways
granted, tires are a little more expensive.. but it's a hell of a lot more fun