well i can only think of one way this happened, either the bolts weren't tightened properly or they just forgot to put the bolts back in...see attached and let me know if you can see what is wrong...there was only one bolt left...3 missing...also my right rear tire had a huge bald spot going all the way round the center of the tire...

 

Looks like your guy put the bolts in finger tight, and then forgot to secure them with a tool. Probably got an important text about that time! (I know... NOT funny.) As for the bald spot, I am thinking he may have been out leaning too hard on the throttle, if you get my meaning. Look behind the tire in the wheel well lip and see if there is a lot of rubber bits or dust collected there, indicating the tire was spinning excessively. Being a mechanic myself, I would expect a "professional" would never do that. Maybe there is another explanation? I am hoping that your service facility is taking care of you on this.

 

yes finger tight sounds right...i already the part numbers and looking for a good deal online...i do love my mechanic...i am sure it wasnt him but one of his guys :-)

i always take corners hard like many times on the way to work so i am guessing the sway bar on turns was wearing that tire down...i am ordering two new tires as i got my full size spare on that wheel now..lots of vibration with two different tires on there and one with a 100 miles and one with 20000...