I changed my oil while kilted but I was in my garage and I just positioned myself as I always do and was quite comfortable. I wouldn't recommend it as there's always a risk of getting oil on a fine piece of clothing. I just did it for the experience of seeing what it would be like. Just like the time I climbed a ladder to clean leaves off the roof. My wife said I should never climb a ladder again wearing a kilt and especially after drinking a beer. Actually I just did this to see her reaction!