bump

I would inquire with a dealer. There's been some issues with the transmissions in the new Mustangs, enough so that the NHTSA is investigating. If nothing more, it gets a complaint documented, so if something is wrong, there's an established history. It could be nothing, but why not check it out since it's a new car?
 
Hi OkieHick!

Without hearing the noise, I'd only be guessing if it is normal. Since you are a bit concerned, I recommend having your dealer test drive your Mustang to confirm that everything is functioning correctly. And you know I'm here to help if needed. :)

~Natasha
 
My 05 stang always seems to lunge as it slows down. Usually around the 5-0mph range as it's down shifting. I think my foot automatically releases some pressure from the brake to smooth it out, lol.
 
My 05 stang always seems to lunge as it slows down. Usually around the 5-0mph range as it's down shifting. I think my foot automatically releases some pressure from the brake to smooth it out, lol.

"Lunge" is a better word...it's not a noise. My 93 Ranger does it also but to a lesser extent. I'm not really concerned with it: it's downshifting.

I had a 94 Taurus that started lunging enough to kinda launch my into an intersection if I didn't have the brake on. That turned out to be a $1500 tranny repair bill. Since that incident I've been leary of lunges of any kind!