I watched a movie a few years ago and don't remember the title. I don't remember much but the part I remember is.. There is a little boy in the back of a vehicle, the driver and passenger don't know he is there and when the passenger turns around and goes to say the little boy is back there the driver stabs him and then burns his body at a crematorium, or at least I think it is a crematorium.
Sorry, I don't remember much .

Pretty sure its Domestic Disturbance with John Travolta and Vince Vaughn.

Yessss! Thank you so much, it's been bugging me forever!

My pleasure, it's a great movie