Rhine is good (m)
Rhine is good, but I have also heard from other Z owners that they had issues.
I have used Rhine and never had an issue with them.
If you want you can drive up to Austin to Terry Sayther's place. Nothing but great guys up there. I am going to have them do my cooling system. Replacing everything plastic and use metal, all preventive maintenance stuff.
Also, remember to use your BMWCCA card to get discounts on the parts that is used.
You can also check out the sponsers on the Tejas chapter's website for other repair shops in the area.
www.tejaschapter.org
Good luck!