@Whiskeyomega I haven't used them very much for cars, they don't really operate where I live and the only place I frequent that they do operate is London, and I'd prefer to hail down a black cab any day of the week.
I think I have used them maybe once in the last year, and that was to get a car from Heathrow to my house (90mins - 2 hours away depending on traffic) and that's only because local taxi's wouldn't take me.