car shudders going into gear

Ok went to local dealership in Cleveland Tn, and bought a beautiful 2008 Pontiac GXP. Well about a week later the transmission started to shudder at any speed, then when you went to pull out from a stop nothing, then BAM it goes. Well I called said dealership and told them I haven't even put 226 miles on the car and it wont move at all!! They called a few days later and said they offered me a warranty when I bought the car, yeah $4500 for a 3 yr warranty, so I asked the sales manager "so y'all are in the market of selling used vehicles that wont make it 300 miles?" Of course not he says, by the by the the dealership sounds a lot like TONDA, sue me you schmuks. Any way had to get a wrecker to tow to local Transmission Guru, tells me he drained the fluid and metal shavings were coming out, Big chunks. Pulls tranny out and low and behold its fried, burnt, toast. Torque converter failed and sent debris all thru tranny,total rebuild cost me $1975.23. So having gotten that of my chest, y'all beware of GM's Automatic Transmission.