After having this new-to-me 07 C70 for about six month, I noted some tire noise starting to happen. As I'd bought the car with new tires figured it might be a case of misalignment, so took it to a Volvo dealer for a look-see.
They performed the $89 wheel alignment and said the alignment only required a very minor adjustment...something like 1 or 2mm on a toe-in and basically it was near perfect. They also noted I had a beginning of a scalloped tire, but there was nothing else suggested that they could do...implying that this was now taken care of.
These are Cooper 235/45R17, a wide flat bottomed fairly low profile tire.


So now I have put an additional 2500 miles on the car, hoping to wear the uneven tire back to normality.
If anything it is even worse now. I hate the noise it makes from 40 mph on up. So, in my mind the next step is to just replace that tire, thinking it must have been manufactured slightly out of round.
But I will ask first....is there any tendency for this car to have a weird problem forcing a tire to go scalloped. Something with the suspension.... anything that might not be obvious ? It has not been wrecked. Thanks!

 

It's common for rear camber to cause the inside edges of tires to wear unevenly and cause road noise. The only correction is updated upper control arms, but it depends on what the camber measurements were at the time of the last alignment.

 

as a habit I always ask the shop for a print out of the alignment specs. I happen to also own a '12 VW CC which are notorious for developing tire cupping. There's a camp that blames the Continental OEM tires VWs ship with, others say its the suspension geometry which is somewhat agressive on toe in (I don't have the specs so I can't say that's the case). The only sensible remedy I've heard is to rotate the tires every 5000 front to rear (if your tires are unidirectional, you keep them on the same side of the car when rotating) and regularly get a 4 wheel alignment done at a quality shop - even a little off can cup the tires over time. If the car is getting up in miles, you may want to consider freshening the control arms....

 

Just to clarify- don't just go randomly replacing the upper control arms. The updated arms are different and will change the camber. They should only be used if camber is out of spec (or if using them will bring it closer to the middle of the spec). I forgot how much they change it, I'd have to look up the bulletin sometime.

 

I would have the suspension checked out. All bushings, ball joints. Replace cupped tire after suspension evaluation. I use an independent Volvo repair shop that does excellent work and really gets to know his customers and their cars. Mine has done excellent work, realistic estimates and badly wants my 98 C70 coupe, 2.3HPT with every option and 36,000 miles. He has replaced every piece of my front end suspension. I had a bad bearing, left front, so replaced both bearings and axles then all other parts including brakes. Had rear suspension links replaced. 70mph straight road, hands off wheel, car stays straight! Don't ruin another tire until full inspection of suspension! Good luck.
Always ensure tires are speed balanced.