I'll add my $0.02 since I just replaced some bulbs with LEDs.
I bought mine from Autolumination:
194 Bulbs 168 W5W 2825 Map Led Parking Signal Side Marker
I used the "194 Goldstar Bulbs With Metal Heat Sink" in "Super White" for the license plate.
I used the "7 Watt Osram Canbus" in "Super White" for the interior lights on the tail gate. (The engineer that designed those light housings needs to be whipped!)
It's only been a couple weeks, but no burn-outs so far. I've used V-LEDs in the past with good results, but Autolumination was a little cheaper.
That's all I have planned so far...
Maybe the front side amber markers at some point.
Sure wish someone would make some nice LED tail lights for the WK2...