It’s a tough economy, and arts institutions are apparently trying everything to make a buck. This from a recent promotional email from Dallas’ McKinney Avenue Contemporary: “Come have your dirty, stinkin, filthy car washed by the sparkling, sweet, beautiful girls of The MAC!!! At the MAC, your car will be lovingly hand washed and dried, and your $20 donation will be greatly appreciated. Arrive early to be first in line for this titillating experience!”