What I did was take a bottle (3 liter soda bottles from Food Lion are pretty loud), fill it up about 1/4 to 1/3 of the way, dump some dry ice pellets in there (a pretty good amount is a large handful, but DON'T use your hand, ok?), tighten the cap, shake and throw!
The dry ice is so cold that it boils when it hits room temp. water, it looks like the water is boiling.
'86 325es (TURTL3): PJ peetsa hawler
'87 535is (BADWATER): almost done... really.
'86 325e (GRN HLL): DD/show/rocket
'04 x3 3.0i: Wife's Bimmer (manual, woot!) My BMW Blog