It could be the front tires, also. (Or your brain - the first sign of Mad
Volvo Driver disease.) If the pressure is okay, a visit to a competent and
honest tire dealer would be worthwhile.
My favorite spot check for alignment problems is to put a strip of masking
tape across each front tire, sidewall to sidewall, and drive a mile or so on
fairly straight road. If the tape wears unevenly, there is something that
needs to be corrected.
Mike
