i was in the process of buying this 06 impala my friend got from the auction,it was a REPO everything checked out fine until i drove it.....got it out of the yard and on the way up a bridge the trans started slipping bad,but once i let of the gas it drove normal again,i still might get it,because my friend took the transmission out and sent it to a shop to get rebuilt,the only thing i dont like about the car is the previous owner VHTed the rear tailights and the car has a column shifter,i wanted a 8th gen with a floor shifter,if i do decide to get the car,how much trouble would it be to change it to a floor shifter?