Personally I wouldn't use a Jet-Wash, after seeing my friend take a big wad of paint off his Merc I don't go near them haha! Try a degreaser spray/foam and a hose
I think mine was done the same way as Phils, (it was fitted professionally). The bolt goes through pretty much right at the very end of the tunnel. The middle bolt is under the rear bench and the last one is by the seatbelt rail Hope that helps
Depends if you really wanna keep the car though right? I wouldn't wanna break mine, I love it too much lol. Personally it would only ever be a last resort for me!