Here's another vote for PlaneCover.com - their cowl plugs work very well. They're inexpensive, not cheap!

http://www.planecover.com/other/plugs_only.htm


-Kirk Wennerstrom
President, Cessna 150-152 Fly-In Foundation
1976 Cessna Cardinal RG N7556V
Hangar D1, Bridgeport, CT KBDR