I think there may have been on early mk7’s. I can recall some forum members over the years saying they did get a low fob battery warning but it seems there’s no warning on later cars. With keyless entry - I think all TCR’s were keyless(?) - the fob batteries seem to last around a year on average, so it might be worth keeping a spare battery in the car and another in your wallet so you’ve got a spare to hand when it happens next time. Alternatively, consider just changing the battery every 12 months - both key fobs even if you only use one on your keys because with keyless, I believe the key fobs continually communicate with the car.