I asked about this once... From what I remember, it was a flat rate of like $20 cdn./mo. and all I had to do was bring in receipts. Keep in mind that if an adjustor appraises your damaged vehicle and takes note that it has been 'modified', technically he can flat out say, "this isn't the car we were insuring." and walk away. Then you're in a real pickle. I knew a guy that dropped a 5.0 in his 4-banger Mustang and crashed it (go figure)... he had never told his ins. co. This is exaclty what happened. Now, I know adding perf. parts to an existing motor is an entirely different animal. But, I'd rather err on the side of caution, than be left holding the bag by my ins. co.