Where to begin..
Brought my '09 SL550 in originally for a broken window regulator and intermittent slow crank issue.
Visit #1: Window regulator replaced, Coolant sensor replaced as they hoped that would resolve the slow crank.
Slow crank was not resolved, and after replacing window regulator i began hearing significantly more road noise at high speeds, a severe rattle upon closing the door with window down and a new knock when operating the far rear window as well as a slight leak in the hard top. Upon further inspection, i found scratches along the door I assume was from the window regulator replacement.
Against my better judgement, I brought it back in since the window regulator was under warranty.
Visit #2: They claimed to have adjusted the window regulator and resolved the knocking sound. They also revealed the fuel pump filter needed to be replaced and thought that would resolve the slow crank. (why not check the fuel pump filter initially, i do not know) - they also claimed to have taken it on the highway to verify the road noise from window regulator replacement was fixed.
Upon pick up, it did the slow crank literally in their parking lot. After I went back inside to inform them to make a note on my account regarding it, the GM came out for a chat. In his attempt to keep me as a customer, was very apologetic about the service experience and offered service credit as resolution.
After parting ways, I soon realized that not a single issue they assured me they fixed had been resolved. Including the window knock, rattle and road noise. Not to mention the water spots left from testing the hard top required a detail to get removed.
Today, I finally resolved the slow crank with a simple battery test and replacement - something I had convinced myself any competent mechanic would have originally checked for when knowing a vehicle was in for a slow crank issue.
2 Stars because the GM Ted was courteous in attempting to make it right, but overall 1 star for attention to detail, time management and overall service.
I really wanted to trust and rely on this shop, when you willingly drive a mobile money pit a mechanic you can count on is critical but it appears that search continues.