My wifes friend has a 2005 BMW Z4 and asked me what she needed to add to the radiator since her low coolant light comes on first thing in the morning. She said it goes out soon after driving, so I told her there is probably a slow leak that needs fixed. But what coolant can she add to it? Also, she asked me if there was a cheaper oil she could use as the dealer was charging her over $100 bucks for a service. I looked up the bmw spec and found that M1 0w40 should work and told her I could change it for her for almost half that. Looking around at walmart, the only oil filter they stock for it is a Fram OCOD cartridge style filter. Are these any good? I opened one up and it looks well made, nice, straight pleats, and it said made in the USA