Stay away from the Polarg bulbs, there have been quite a few posts where the reg plate bulb holders have melted:-
"I'm actually in a similar situation, I purchased a set of the "Polarg B1 Hybrid" bulbs approx 6-8 months ago for my license plate (also tinted blue bulbs), I had them on for no problem. A couple days ago, when I wanted to switch from the blue bulbs to led(with resistors), I found out that the upper part of the housing (contact point to the hatch) was melted. Worried there might be a problem, I switched back to stock bulbs, but then both sides don't turn on and computer gives me a warning. "
There was a long thread on VWVortex about it, can't find it at the moment.