I just got back from a long weekend trip in the States. My wife and I were going down for the weekend so I decided to get the walnut shell blasting done to my valves. I have to say it makes a big difference. I was having some issues with idling in the morning and afternoon start-up (when left for a while). Also it feels like my car is even quicker now!! (might be in my mind after driving around a 328i all day). Brain Jessel recommended this but charged an arm and a leg. Reading through some of the Washington posts people mentioned that there was a special price for this exact cleaning @ BMW Belleville Washington. Easy to get to with navi
The cost is $369 + tax and that comes with a complementary curtsy car just like down here. I dropped it off in the morning around 8:30 am and took off shopping for the whole day!! Seattle premium outlets, Northgate Mall, and some shops around the Seattle area. I really recommend going down there because is will save you $1000!!!!
Here is the post that I received the initial information from!