Until 2014 we always recommended Proper Car. http://www.propercar.com We had always found them to be thoroughly reliable and their prices reasonable.
However, although we have continued to use them and have never been let down, some guests reported (in 2014) that they were not receiving replies to emails requesting quotes.
We followed this up with Propercar and in September 2014 we spoke to Yunus the manager at the Bodrum office. He apologised for the problem and told us to tell guests to email him at firstname.lastname@example.org The office phone number is +90(0) 252 3169540 and his mobile is +90(0) 544 3449540. If you ask to use Valerie Smith’s account (Opus Village, Gumusluk) they should give you a reduction on their prices. They have, to our knowledge, always honoured a booking and are contactable by phone. If you book with them make sure you select the ‘pay on pick up’ option.