Unless the car sounds like loose nuts and bolts in an empty coffee can it is fine to go to Iowa. I bought a 150,000 mile M3 and took it to the track 4 times (to see where the faults were hiding) before getting a new VANOS. Afterward, a way smooother engine, better high end torque, punchy acceleration. Oooh, this is supposed to be how they run. Highest recommendation for the Dr. Vanos product and their excellent customer service on core and tool refunds.