Hi
Only problem is the sills can be completely rotted out and you can't see a single thing with the cover on
what you get on the mot is, "cant' check sill's due to covers fitted" and "cant't check floors due to covers fitted"
on a mot they can't remove anything, the can only tap it or prod it with out excessive force, so sill's get missed.
pauls 2006 s-type, he was shocked when he checked his http://www.jaguarownersclub.com/forums/topic/13904-a-nasty-shock/#comment-41101
some others here
http://www.jaguarownersclub.com/forums/topic/14389-jaguar-s-type-2003-rust/#comment-43523
http://www.jaguarownersclub.com/forums/topic/12503-sills-worse-case-scenario-cost/#comment-32763
if you have a android phone , go on google play store and look for " VEHICLE SMART " app with this you can check the vehicle milage and any previous mot advisory's
cheers
Joe