The first question I would ask is: did you really have an alignment?

I remember taking a car in for an alignment once where the guy put the car up on a lift an took out his tape measure and measured between the front and backs of the tires. For many cars where "toe" might be the only adjustment, there is some validity to this methodology. But crudity of the technique does not instill confidence.

After going to two shops for this kind of alignment, I went to one of those regional chains (NTB-National Tire and Battery), had them put the car up on a rack, and had the computer spit out a sheet with all the alignment specs for the car, and where my car was, both before, and after, adjustments were made.

Getting a document with all the specs is alot more comforting than getting just a bill which says "alignment done."

BTW, tires are make a big difference as to how a car tracks. I assume that your Volvo and the Explorer have different tires.