Hey Marty,
A3 to Würzburg on a Saturday noon/afternoon is a good choice (no weekday commuter jams and no Sunday coming back travellers). Its for the first couple of miles a 3-lane-each-way-racetrack, where you can easily go over 120 mls/h (if that's what you are looking for). In addition Würzburg is a nice city to visit for a couple of hours.
cheers
HON_Hunter