EPC shows a HB4 12v 51 watt part as the replacement for a US build '05. I'm assuming that the UK version is the same, but not 100% positive that's the case. If you PM me your VIN, I can see if there's a different part associated with it...

 

the bulbs are different between SLKs with the AMG style fog lights vs the standard model.

 

Whatever the bulb designation is, I would recommend Philips X-treme bulbs for this mod. Over a year ago, I found a really great deal on a new '07 SLK 280 that had about everything I really wanted on it except for xenons. Too good to pass up. So after I got it, I replaced the low beam bulbs with these, and the result is close to xenon lighting -- close enough for me. I'll continue to watch this thread, because I like to use fog lights -- even if there is no fog. Helps me see better at night. After my experience with the low beam light bulbs, I think I'll replace my fogs with this brand and model as well.

 

I bought some yellow H11s for my fog lamps and took them to my helpful dealer who said he would swap them for nothing !!

He came back 10 mins later and said they were the wrong type - even though the manual says H11 the locating lugs were in the wrong place.

I have now ordered a pair of HB4/9006 from the States.
Lets hope these fit !!

 

HB4/9006 - a perfect fit

OK - These yellow HB4/9006 fit fine. So the manual for my SL200 is out off date (The car is on a '55' UK number plate)