I used these tires on my A4. Size 255/35R18. Great in the rain and a generally decent street tire. Sidewalls are a bit stiff. Lasted 8 track days + about 15k street miles.
I now have Bridgestone Potenza RE11's on the same car (same size, same wheels) and they are much stickier, more comfortable, and a little more vague. The T1R's were more fun on the street, since they were more predictable and more manageable at the limit (just what you'd expect from a JDM tire, eh?). T1R's were also pretty inexpensive. They will be missed.