I think Wayne touched on the main potential culprits. My guess is that the car is in dire need of a complete alignment/corner-balance/ride-height adjustment. A car that has too much negative camber, or too much toe-out can feel like it is "hunting", especially in a decent crosswind. Also, tire pressures are significant in the way the car handles. Bill D offered some good advice on this, although, I tend to go a little higher on the rear (cold) pressures with normal street tires. 30psi on the front, and 36psi in the rear is a good starting point. I have also heard of the same wandering/hunting symptoms produced by worn steering racks, but that is less likely than the previously mentioned usual suspects. Good luck!
