You may have a shifted belt or a tread bulge in one of your front tires. You might not even need to jack up the car to find it: Just kneel by each tire, run your flat palms carefully over the tread from the high-noon position down each direction as far as you can towards the pavement, and see if the tread surface is smooth or not. A tread imperfection that'* big enough to wiggle your steering wheel shouldn't be too hard to find.
If you find nothing on either front tire that way, you'll have to put the front end in the air, put the car in Neutral and spin the tires.[/quote]
My thoughts exactly!
Had the same thing happen in my Monte and it decided to finally let go while on the highway. Thought my whole frontend was going to fly off!