Gary - Our 2003 Tracker is also a ZR2 with V6 engine. A nice little car with all the bells and whistles of a "real" car. I only wish it got better mileage. I religiously check it for every tank and it is always 20 to 22 mpg, the same as our much larger 1999 Toyota Sienna XLE minivan with V6 engine.
A question for you. The Tracker has always had a low "thump, thump" noise when moving at very low speed but no noise or vibration when driving at moderate to high speeds. Have you heard the same thing on yours? I have not checked for a bump on the tires but feel that if there were one it would cause vibration at higher speeds. The 3 year bumper to bumper warranty expires in July, so I took it in to my dealer yesterday to have them check it out as well as to take advantage of their mailed out $9.95 oil/filter change coupon.