I booked them over the phone (which was a breeze) and I was told I'd get an email confirmation (which I didn't), but they were they were on time and ready to go.
Our driver was very accommodating, he took my whole wedding party and photographers to the LV sign, Downtown and reception venue in a 2 hour span. There was plenty of champagne, but we were so parched that the bottles of water went fast and the limo felt like a sauna even with the A/C going (it was mid-August with temps reaching 107 degrees)