Start looking around 50k if stock, sooner if tuned (or having misfires) and not using CRC/seafoam/etc for preventative maintenance.
Previous exp w/ my R56S, cleanings were done 35k (dealer), 50k, 80k. She was a oil eater and driven hard, and eventually pulled the head for valve work on cyl 3&4
Co-worker's R56S, 2 weeks earlier build week. Didn't need cleaning til 80k, she drove like a granny, no mods (just tint)
Previous exp w/ my R56S, cleanings were done 35k (dealer), 50k, 80k. She was a oil eater and driven hard, and eventually pulled the head for valve work on cyl 3&4
Co-worker's R56S, 2 weeks earlier build week. Didn't need cleaning til 80k, she drove like a granny, no mods (just tint)