That's odd because I'm running CW5 36mm LED festoons in mine and have no Canbus error issues at all. But then there's so many variants on eBay it's hard to know which bulb is decent. My biggest gripe however is that they tend to flicker and burn out quite quickly, I bought a set of 4x Fizzmo LEDs and 2 had flickered out within a month so I'm on my last 2 already! So I improvised by adding a small heatsink with thermal paste on top and its coping fine... for now.
The VW LED units are the best but as people say its expensive, I had them on my MK6 Golf before it got nicked.
Part number for that is 1K8 943 021B and looking at my old invoice it costed me £55.87 for the set. That's not including the Kufatec adapters to get rid of the Bulb out error with them, they're around £30 so you'll be looking at £80 for the official OEM route!