I dont know if this helps at all as I've only done a 60k service there but, I bought my Z in middleburg hts on the west side of cleveland on pearl road (northcoast nissan). They are one of the dealers that participated in that 240z restoration thing and resold them in mint condition... i dont know if that makes them better w/ Z's but I'm assuming they have a Z guy or 2.
no idea.. just throwing that out there
“… He spoke with all the righteous indignation of an ungifted artist denouncing the scapegoat whom he has chosen to take the blame for the lamentable consequences of his own lack of talent.” - Aldous Huxley