The car was in an accident before so the rear camber is off and it has been eating tires because of it. There is too much negative camber.

I am deciding to use either SPEC kit or washers from the hardware store and I want some help deciding which one.

I think the Spec kit is just plastic vs washers from the hardware store that are metal. I think I can either use the spec kit or washers and mount them onto the top two bolts creating positive camber.

It would seem washers are a bit safer as I won't be adding any to the lower half so it will sit closer.

I know all the precautions of using washers and shims.

I am not too worried about getting it perfect just to get good tire wear back. The car is a DD workhorse.

 

sucks they didn't fix it right, i'd take it back and make them fix it (assuming you were the one that had it fixed the first time) but a good alignment shop will do it right - remember if you have enough money to do it wrong twice , you have enough to do it right the first time! - just sayin