lol, I think Darien1629 is talking about his gear 'slipping out' of 3rd, not the back-end of the car. Took me 3 reads to see the 1st post for that.

Is this a regular thing? Or did this happen only once since you had the car? If it happend only once, then maybe you didn't put the gear fully in place and it poppoed out.

On the other hand, if toyr car pops-out from any gear by itself, and this has happend a few times (ie. repeatedly), then you have a problem and should take the car to a dealer and get it fixed.