Smoke from exhaust

I just bought a 2007 speed3 a couple weeks ago and I noticed that it'll puff out a pretty big cloud of smoke (white with a blue hue) occasionally when the car is warmed up fully and I stop at a light. The person that had the car before me cut the exhaust off to about where the backseats are, could that have anything to do with it?

 

Did you fix the exhaust and have it properly exit out the rear of the vehicle?

It could be a few things. Valve stem seals, valve cover gasket leaking oil into the spark plug tubes, maybe the turbo is leaking oil internally.

 

puff of blue is oil being burned