Also same as you. I put BFG T/A's on my car 16 yrs ago. Have maybe 5000 miles on them now at best. Tires still look brand new. Of course the car is garage kept so the tires don't see much sun light, and I always keep them dressed with some kind of tire dressing to prevent dry rot. You should be fine.
Mine are about 10 years old, like new, with 6K miles on them.. I always thought the same about sun being the culprit, which it is a problem, but lately been reading about the compound drying out and the oils in them dissipating.....
I hate to spend the money on new tires but I do have concerns about mine..........
