Could your scratches or whatever they are might have been caused by someone trying to close the tailgate while having the tailgate speakers deployed down (if you have this option installed) by any chance ?
It think the marks it would leave might just fit the description of the position you mentioned...
Also, call me crazy but I've been testing a theory that I came up with a few months ago regarding driving with 4x4 mode locked on and the effect it has on the gas mileage.
I'm getting close to 20,000km on my odo and when I first got my Compass, I tried running with and without the 4x4 mode locked on to see it there was a difference and I noticed a little but not the way I thought, I was doing better mileage in 4x4 mode. I thought this might have been because I was driving in winter and that being in 4x4 mode would help by having better acceleration, less slippage bla bla bla...
Anyway, I decided to wait till summer (and a few more km on the odo) to test this theory again.
Well, I did 2 full tanks now in 4x4 mode.
Now, I usually do about (maximum) 400 km on one tank, and it is very empty in the end because I'm filling over 51 liters (max capacity according to user's manual is 51.1 liters) when I try that, and this is pretty much every time I fill up.
By the way, I figured that you can fit about (maximum) 4 liters more that the maximum tank capacity if you take your time and shake (swing) the truck by the roof rails to let the air out, and people do look at me with a strange look when I do that but that's another story.
Now, back to the results. With my 2 tanks, in 4x4 mode, I was able to reach 470 kilometers on the first and 480 on the second and there was a little less than 2 liters left in the tank when I filled up.
I did a little bit more highway driving than usual but not that much. I'm on my third tank now and still in 4x4 mode. I'll let you know the results.