Changed my oil and transmission fluid today, used Amsoil for both. The original owner told me that he did not know if the transmission fluid had ever been changed, this car has always been serviced at a Smart dealership, I told him if he did not request it then it probably wasn't done. I must say if it is the original oil then it looked fairly clear with no noticeable shavings, car just turned 95,000 miles. I ended up using a Mobil One oil filter also. I do think the shifting at full throttle felt better and firmer just in case someone wants to know.