Hi and Welcome, Sat Nav does not come as standard it was an optional extra but there may be some 03 with it already on. As far tuning, if you want to mod its worth getting the coupe over the roadster as the 0-60 will vary slightly. Plus IMO coupe looks better. Get the induction kit and exhaust, either Nismo or HKS. As far as remaps go you have to be pretty careful as some companys offer 350z remaps but then end up blowing your engine. So Ive heard. I had a test drive in the S2000 before I bought my Z, and I must say, although it was fun reving the engine, The Z just feels more responsive.