MR's don't come with sunroofs man. Aluminum doesn't make a good sunroof mounting material
I've been doing some searching and I've come across what I think the problem is. Seems on the East coast several 06 MR's have been having a problem with water in the passenger floor board. It was eventually tracked down to a problem with the install of the mitsu guage package. Seems that they either ran it through the wrong gromet, or jabbed a hole in it with a screw driver to push the vacuum hose and wires through and it leaks pretty badly.
What happens is all the wool under the carpet and firewall soaks up the water until saturation, then it starts to pool up in the floor board. Lots of people may have this problem and never know it for months, or at all if it dries enough to never reach saturation.