Rear tire wear = BAD, help!

[Hangin_and_bangin]

It's only been about 6k miles and my rear tires are toasted!
The front ones look basically new.
I drove maybe 2k of those miles before getting the toe adjusted properly.
My car is maxed out on Megan coilovers all around on 19X10 +20 wheels wrapped in 245/35/19 hankook evo 2's.
I'm running camber bolts in the rear that are also maxed negative. (so maybe like -3)
I can only fit one finger under the fender on either side.

My question is,
Is it worth adjusting the camber if i can only fit one finger under the fender, and if so, how many more miles should i expect to get?

Also, should I just raise the rear coilovers by maybe 1/2 an inch to give more room to correct the camber?