Hi
As my reply to a previous question on the eos forum a couple of days ago under the heading car hire in Murcia, I recommended Coy's rent a car to them.
Only speaking from our own experiences you are met at the airport by a representative, you pay them on arrival either in Euro or by card I think they except sterling as well but don't hold me to that, they take you to your car which is parked across the road and off you go, simple, no queuing at car rental desks, we use them frequently and have never been disappointed, I would not use any one else. Hope this helps👍