Worn brass bushing in the front axle can cause wobbles. Incorrectly indexed brake hubs can cause vibration. Worn out steering column parts can cause wobbles. The above advice on the drive shaft and tire pressures are great ideas, too. Your thoughts on out-of-round tires until they warm up is a good start, since you're only paying for gas to drive it around longer and warm up the tires. As you try and narrow it down the guys here are great on ideas without the negativity. I hope it's an easy and cheap fix!!- gonz