all i know is that they did diagnostics, it clearly states it on their invoice to me. They called me and informed me of the problems they found. I gave them the ok to fix it. Upon completion, roof would not operate. I take it to mercedes, on their invoice they do diagnostics, they find 3 error codes and 7 problems with hydraulics. If these problems existed prior, why didn't my local mechanic find them when they ran diagnostics? It clearly states that they diagnosed the problem on the inovice. Could it possibly be that these problems did not exist prior, that's why they were not discovered????? Hmmmmm