If your car is a bluedrive then I presume it is the GD version, 2012 onwards? On my 2015 car the rear lights are on a CAN bus wiring system. I don't know if changing the bulbs to LED will upset it, because the local CAN controller in the light cluster checks the bulbs are working and will flag up an alarm on the dashboard if they're not. If it does this by detecting current through the bulb, changing to an LED type will reduce the current and this may be mis-interpreted as a failed bulb. On my own car, which I've had for 2 1/2 years, I don't recall having to replace any bulbs. In contrast, I had lots of bulb failures on my previous car which was a 2011 i30 with a conventional wiring harness.