ON another note, I just put new tires on the Z. I am trying the Hankook Ventus V12 Evo K110. I have read good things about them, and the price is hard to beat at around $150 each. If they are as good as the tests show, they may be my next tire on the alltrac.
I also upgraded my stereo in the Z. One of my policies is that is there nothing worth stealing that a thief can steal, then you much less likely going to get your car broken into. One issue with the 2003 Z base sound system, other than not sounding very good, is that you can't really upgrade it. I found out about the Kenwood KOS input device. I picked up a new KOS-A200 on ebay for less than a high end FM tuner. It works as a FM input, but is much more robust. It plugs directly into the radio jack, and has a much better sound quality. Now I can plug in USB devices, navigation, dvd etc. So say if you wanted to keep the stock alltrac radio, you could consider this as an option to add more features without having to go with a new head unit. Plus you can hide it and the other items you install, though I am not sure how you would install a nav screen w/o making room for it in the dash somewhere.