TBH....I dont trust those few taxis that do have carseats in them, this is from knowing a mum that used to drive one of the few that had them, she said that they were very unhigenic not reglary cleaned ect, people would often leave with the seat wet from leaking nappies ect, one had a 2 yr old with shcool sores ect in, just some horror stories I have heard and then there can be a lenthy delay in getting on and if its an ermegency like in the middle of the night I would prefer to have a back up just in case.