I thought I had booked them at Sky Harbor airport - even had a reservation number.
After Arriving at PHX, I asked airport personnel where to go for Roadrunner Shuttle. No one had ever heard of them. Called them and gave them my reservation number and was told there was no reservation for me, that the reservation number I gave them was from several years ago. I was informed they could not help me at all, in any way.
I went out to the cab stand and was directed to the next available cab. Estimate to go to destination was $29 but turned out to cost me $45.
I sent a letter to headquarters in California with copies of my reservation and all the correspondence prior to my trip and NEVER heard back from them. Rude.
Horrible experience - would NEVER recommend them. Wish I could give them 0 stars!