I say nuts to all this
How come we don't just get a walnut shell blasting every 40k or so, even if out of our pocket? The service is available. We seem to have enough anecdotal evidence now don't we? A speed shop guy cautioned me in June last year to be on the lookout for this. This was when I had the car for only one month so it kinda went in one ear and out the other. And run a good fuel additive and drive it hard. We bought the car to drive it hard anyway, did we not? And get good mileage to partially soothe our conscience.
Mods-Etc: Quaife LSD w/VAC finned diff cover, M3 Rear SF Bushings, M3 sways & OEM Susp Front/Rear Cmpnt Kits ('cept strut brace), GC Caster/Camber Plates, AC Schnitzer M3 Sport Springs, JRZ RS1 dampers, JBD 100%, Goodrich SS brake lines, non-stggrd APEX ARC-8 18" wheels with Michelin PSS tires (winter OEM 17" wheels and Blizzak LM-25).