I've had my Z3 since January (got it with 39000 miles on it), and I've only put on about 2000 miles. I only drive 4 miles per day back and forth to work. I just bought a AWD vehicle for the winter, as we have some really stupid drivers here in NJ and didn't want to chance one of them running into me when it snows. I figure I'll only have put less than 3000 miles on the car by it's year anniversary. What time interval should I use, as it would take me a couple of years to get to the 7500 mark?