Anyone hired a car through Drivalia?

I'm looking for budget car rental for a week in the UK next month and Drivalia is coming up as the cheapest option. I've never heard of them, anyone had any experience with them?

Their online reviews aren't great but neither are those for any car rental company so that doesn't really give much to go on.

Anyone got any other recommendations for cheap car rental with pick up/drop off at BHX? Needs to be an automatic but don't care what size/model/etc.