I have them on mine for the specific purpose of autocrossing in the 'street-tire' class. I run them all the time, hence I don't need to buy extra wheels and change tires for the events (which was supposed of be the idea of 'street tire'). I expect to get a year out of them, unless I do too many track days.
The biggest size they come in is our OEM 245/45x17, so while they are inexpensive, they are also -- in the case of the Mustang -- quite a bit slower than "R" tires, which one would run in a 275-or-so size. Incidentally, they are about equal to the Nitto 555s in the wet, and are quieter and smoother-riding.