Q: Smoke entering car from the engine compartment.

The smoke coming from behind the steering wheel is a sign that something is shorting or making poor contact and you may be in danger of a fire starting from continued use or possible air bag going off with out warning. Get this vehicle checked as soon as possible by a certified mechanic and I do not recommend driving this vehicle till it is checked. Also recommend the battery be disconnected till serviced. The most likely cause is the ignition switch causing the problem from overheating. You may have outstanding recalls for the windshield wipers and the ignition switch. I recommend checking with a GM dealer on the recalls if they were done. The wiper motors were known to catch fire and the ignition switch to bind.