I have tried Ewing ******** in Plano and have been very satisfied with their work.I have also tried 911 Enterprises and Autoscope and have been very impressed with their courtesy,shop cleanliness, and attention to detail.I have also heard good things about Louden ********,Lazlo's,and Dallas Autosports.I met the owner of Dallas Autosports at Stuart's Bodyshop one day and he was very knowledgable about european racing automobiles such as Ferrari and Lomborghini.He actually services his car himself in his shop.They are located on Garland Road in Dallas.I hope this helps.