Once you get the car to prompt for the key card, have you tried waking your phone up? Nearly always that will get it to connect and use phone key for me. I actually have more problems with the car being slow to wake to even get to that point (and then having to wait for the natural time it takes to authenticate that it should have done as I approached), versus the phone itself (if the phone was the issue, then the screen should immediately prompt for card as soon as I try the door - more often than not that takes a couple seconds to come up, though sometimes I do have to wake my phone before BT connects)