Topband: automotive relays

[W5UN]

Does anyone here have any experience using automotive type relays for 
switching RF?  If so, at high power levels? These relays are 
typically manufactured for 12 vdc switching at 30 amps, but breaking 
one open and looking inside, it appears the spacings and contacts 
could handle RF. Not sure the insulation can, though. I don't know 
what would happen at high frequencies.

Dave, W5UN