For starters, on our older Xterra, the window switch was a little finicky. We left clear instructions on how to raise if they accidentally lowered it. It wasn't difficult. Of course, they did lower it and tried to use a pair of plyers to raise it and chipped the hell out of the top of the window. So, the vehicle sat at the take out with the driver's side window open. Another time they were late at the take out and claimed the car wouldn't start. We hadn't had any issue prior or afterwards. They weren't terribly late and it wasn't a huge issue, but Pat has been on time, w/o damage the two times we've used him.
Not taking anything away from Blackadar. They are also a great shuttle company. Some friends of ours rented a raft from them one year and it was a painless process.