Raced a newer s197 Mustang GT last monday with my brother in law in the car. I wasn't going to go after it but he said it sounded badass and poked me too so i bit. On the interstate, both going about 55, he hit it first got a jump, maybe half a car. I pulled him back in and got a door up on him by about 95. Shut it down there. Car must have been modded at least a bit, definitely had exhaust. It sounded completely awesome and looked surprisingly good for a mustang. Probably a 2010 or 2011 judging by the back of it.
I tried to get him to go from a lower speed but he wouldn't get below 65 after that. I'm assuming getting pulled on by a grand prix made him a little salty....
Second mustang kill actually happened last month. End of October ran into a brand new mustang ecoboost. I heard the turbo as he sped by, once I caught up to him I waited until the road went from one lane to two and got along side him. Gassed it a little to show him the power of the GP! Slowed back down to about 50 and he took off. I pulled on him but never got past him as he hit it as i was still slowing down. He easy had a second maybe two of his WOT before i got back into it. Got from the back of him all the way up to about his front quarter before he shut it down somewhere in the 80s. He gave me the thumbs up as he got off after that but we didn't run again. I'm gonna count it as a kill since I would have had him in another 2 seconds.
The ecoboost one is the one I wish I had over as I know that I could have put lengths on him from a lower speed. But alas, it wasn't in the cards. Still fun.