I have always used them on Vettes, since I wanted to make sure everyone back off. Vettes generally stop better than most vehicles. With the H3, I say to the tailgaters, "come on under the back end and say hello to my rear axle...don't forget leave your head at the bumper."
Ecklers and other places sell them for Corvettes, and the systems are the same. However, the connector to the Corvette CHMSL is different than the H3. I don't see why you could not purchase one, and wire it in the old fashioned way with butt end connectors.
Basically, the units are designed to plug in-line with the wiring harness to the CHMSL (center high mounted stop lamp).
In fact, it looks like the one Eckers sells is for splicing in, versus connecting.
http://www.ecklers.com/product.asp?pf_id=40726&dept_id=1384&mscssid=B83NL NPRLD759JCDR12XC870VFQB3M62
http://www.autoelectronicupgrades.co...ll/install.htm
http://www.webelectricproducts.com/products.htm