the '08 350 enth. felt broken in to me around 45k, noticed pressure drop of several psi (about 3+ @2k rpm) at that time. traded @ 50k though .. articles like this one made me think it was worth it;
Nissan 370Z Review; Engine (VQ37VHR) > 370z.com > 370z.com - Magazine
for '12 370+sp, as I got 2 free oil changes, so I changed after 300m, though wanted to do at 20; micro-debris flush was idea. @ 700m now, but daily 20 - 30 mile commute has nice rpm variation built in. 2 or more min warm up, stay under 2k for first 1.5 mile, take it up to 3k for next 7 miles with 5 traffic lights up to highway. then vary up to 4k and down over some 15 - 25min. will see how oil temps go w/ re: to oil cooler option but doubt it'll be an issue around city hi-way loops.
1200m break-in seems good 'nuff, then work in 4 - 5k range for a few hundred, then 5 -6k, etc.. No hurry. 2nd oil change around 1000, synth blend after that; 'should' do pre-10k say some.