I have a customer with a 2009 jag XK-R, and there is a small round momentary push-button switch for the hatch on it. If it's not ungodly expensive, I think it would be just what you need. Also check the rubber pad-like switches on the trunk of the Cadillac CTS or STS, or the outside door open switch from an XLR (I know they're only like $15).