Track days are a blast but the risk factor goes up compared to autox. You've got a big investment already in your car and with it being your DD, the consequences of having a "bad day" at the track go WAY up. If all you are doing is autox, I'd say go for it and mod the Mustang. But, since you're...
Tom, which x-pipe did you choose? I'm thinking the suitcase resonator is the most restrictive and dense part of the exhaust. I'd like a little more volume but I don't want to go all the way to "wakes up the neighbors" loud so I'm thinking a x-pipe replacement would be the best bang for the buck...