Use quality parts
I used wheel adapters on my Porsche Boxster with no issues at all, even on the race track (road course at Texas Motor Speedway). I paid for high quality parts as that was the biggest concern/suggestions I received when I was researching them. The adapters I used a screw to hold it on the hub, and then longer wheel bolts to hold the wheel on (Porsche uses wheel bolts rather than lugs and lug nuts). Never had any issues. A friend runs cheap Auto Zone acquired universal adapters with longer wheel bolts on his race prepped 914 with no issues. From what I gathered, there are no problems with this set up, but when using studs and lug nuts instead of longer bolts there were some other issues you had to be aware of, but I don't recall off hand. It was about a year ago that I installed them. Bottom line, use good parts, talk to an aftermarket wheel specialist with experience with adapters, preferably on your make and model vehicle.
