My fob performance has gone to hell with 3.5.1. The car unlocks on approach less than 50% of the time. I pull out my key and start pressing buttons to unlock, which itself then works about 50% of the time. Usually, after a few presses, the car then seems to realize I'm there and I can hear a click inside and then the handles present, finally. It is not convenient when this process happens in a downpour, as it did the other day, and I was thinking to myself "yeah, of course this would be one of those times." About 5% of the time, I have to reach into my wallet and pull out the key card to open (or start to before it wakes up on its own). Then, sometimes, it still will tell me that the key is not detected and won't start without the card.
It was erratic when I got it, and got to nearly perfect with the last update, but now I'm back to lots of frustration.