We bought our 1998 Z3 2.8 in Sept 2009. The engine was in a box and buckets. Shipped it from St. Louis to Atlanta for my brother-in-law and his employees and (my nephews) to put back together. Put in used engine with about 40,000 miles, new tires, stuts, and several other major parts. Drove it back to Kansas City before the snows came! Now it runs as good as it looks!
Poor car has been waiting for the snow and ice to melt and the salt and sand to disappear -- then it can run around ... it will be waiting a while ... maybe even until spring. (It must avoid the crazy drivers, who forget every time it snows how to drive in the snow.)
So my answer to where I am as an owner of a Z3 is just reading ... nothing to contribute ... yet.
LuckyK in Kansas City