You can purchase this any time up to the end of the 36 month service warranty expiration, and I thought I would see how much maintenance would have cost per year in the first 3 years. I will probably get it later, because $350 - $450 in routine maintenance costs for a BMW in the 4th year of ownership sounds like a deal to me. Like you say, if the brakes need replacing in the 4th year, or anything else costly, it will pay for itself. I think it is probably some good insurance.