Rear-end alignment? and clunk?

[Wasuchi]

The rear wheels on my 300D (about 155k now) appear to be slightly towed in. Also they wear more on the inside and wear more altogether than I would expect anyway. The left one seems to wear slightly more than the right too. The car drives straight and gets ok mpg (24-25 with ac on). I'm thinking something is either worn out or needs to be adjusted. Any ideas?

While I'm at it I have a clunk in the right rear, I can't locate it, I've checked the half shafts, shocks, drive line, everything I could think of. Even tried bouncing it up and down but it only does it when moving, mainly in reverse. It's hard to look underneath for noises on a moving vehicle. Just wondering if these two problems could be related?