Hi Rob
Sorry I don't get chance to come on the site much so only just seen your message!
The car has been really good so far. Only real work I've had to do was front wheel bearings which were knackered (common problem), rear calipers (seized as it had been sat too long without driving in Japan) and exhaust replacement as the old one was rusting away. Now have a cat back stainless quad exhaust system...
Other than that it's just been oil/filter changes, transmission fluid drain and top up as I had no record of when it was last done and some new brake pads.
The car has been very reliable overall and I have recently driven it on a 2,600 odd mile trip all the way from the UK to Budapest to Munich and back home. Only painful bit was sitting on the JDM speed limiter on the Autobahn and getting passed by a 1.4 litre Fiesta. Oh and fuel prices...
Spare parts are generally all 350z apart from the odd bit (rear caliper I think was X-trail). I have Nismo S-tune suspension mine which I'd highly recommend. Not the cheapest but great mix of handling and comfort.
Just picked up today my new alloys although not got the tyres for them yet! They're 19" and I'm going staggered...fingers crossed I have all my measurements correct.
Check out UK M35 Stagea owners on Facebook as well as the general M35 owners group (Oz based) - both have lots of info on these cars.