You can take the wheels off and take them in and tell them its a "off road" car. I also flip my tires when the inside gets thin and that is all I have to tell them and they get right on it(they also note it on the bill "for off road only"). The Conti ExtremeContact DW would be my choice for a good compromise between wet, dry, and longevity.
I run little to no toe on my '06 and my tire mileage is not to bad now.

ROD

 

I don't see any way possible you are going to get 20K on the S2K with autocross and the negative camber you are running. The DW is a good option along with the Hankook Ventus V12. I would suggest getting an alignment done before changing the tires or at the same time.
Like others have said the liability is too high to put the worn tires back on the car. They may even out but they are already bald on the inside. Too big a chance for damage.
If I can help let me know.

 

When I first tracked the car, I let myself be talked into going to max spec 0.64 rear toe to prevent the dreaded AP1 oversteer with minimal tire stagger. After two events, the rears were GONE! So tire wear drove me to reduce it, intended to go from 0.64deg total to 0.30deg total, but the shop accidentally gave me 0.15deg total.
I was very concerned about massive oversteer, but NO. In fact, the car behaved a lot more predictably and less twitchy with the hugely reduced toe. And tire life more than doubled! And mileage went up.

You should be able to find a shop that will do it all (actually ADJUST toe and camber at all four corners *to your spec*) for less than $100 total.

 

I'm happy with my RE760 Sports, I autox/track them too (obviously not as good as starspecs/rs3/etc for track/autox)

 

I have the Evos on mine and really like them. While the inside is wear a little faster than the outside its not by much (I don't autox though). I have driven in rain without much issue and since it doesn't get very cold here I can't speak to that. For the money they are great tires and I will be getting them again.

 

Have and had evos on mine as well love these tires, got about 12k of hard driving out of them but I ran them dangerously low, they looked like slicks and I almost had steel showing what a great mechanic I am. It's quite terrifying hittin runnin water on pavement at 70 mph and having your car go sideways and hoping to steer your way out of such a situation. Moral of the story buy new tires unless you wanna poo your pants alil
-chris

 

I would recommened the Direzza Star Specs.

I switched over to V12s primarily because i was planning on selling the rims/tires very soon but needed something to drive on for the time being.
What a mistake!

The direzzas lasted me about 30,000kms, with 1 track day, and a few auto crosses. But i do drive fairly spiritedly.
Great tires. Exceptional dry grip, good stiff sidewalls, fantastic wet traction until it gets to about 1/4th tread left, then it just gets scary. One big downside that some people would care about would be tire noise.

Now on to the V12s.
They are acceptable tires. Decent dry grip, Slightly more than your typical all seasons. Softer sidewall in comparison to the Direzzas. Wet straightline traction is decent, horrid lateral grip though in the rain. Quieter tires. I believe these also have a higher treadwear rating.

 

I got my V12's! So far I really like them, but I haven't really been able to put them to the test. They actually have pretty good wet grip too from what I can tell. I also got an alignment done and asked for custom specs. Apparently I was running .33 on the left front and -.2 on the front right I got all that worked out and I am running -1.5 camber in the front, -2.2 in the rear, and unfortunately when i asked them to set the toe to .2 in the rear they thought I meant .2 on each wheel and so now I'm running around .45 toe total in the rear That is still better than the .6 total I had before, but I wish I could take it back in and have them change it.

 

I wouldn't be that surprised about the decrease in oversteer and the increase in predictability. I've been doing some light reading on toe and realized that I had toe in and toe out mixed up. I wouldn't be that surprised because positive toe is toe out, and so if you point the rear tires out more then it makes sense that they would slide easier as well as wear quicker. I'm wondering if anyone has tried running negative toe on their rears with good results? Because then you would have the rears pointed inwards and it would increase stability. Although it might increase understeer or make the rear feel sluggish I think it might solve the oversteer problem.

 

10000% agree on squishy sidewalls, especially coming from a set of Toyo RA1s. For that reason I won't be getting DW next time, although it is a good DD tire if you need wet grip.