My Q has 183k on it and its been flogged..
I tend to agree with the above. honestly out of everything thats listed, the rear sway bar is probably the biggest performance enhancement that can be had. Shame that if the guy got an ECU from stillen, he paid $800 for the ECU and my ECU is still superior at $250 (and was cheaper years ago). For a car this age with really nothing "special" about it, I consider the modifications done as freebies.. So I analyze the car as an average clean Q with 176k on it.
Bottom line is at this point in time, its hard for "newbies" to get into the old Qs.. You either have to have had an old Q for a long time, or had one fairly recently with a lot of knowledge to justify what they are.. I will follow that up with my 94 Q is rock solid reliable and I'd drive it anywhere in its current condition. If the car truly needs nothing for the next 60k miles (hard to predict), at $4000 you will get a lot for the money. Also, I don't care how anal you are, at 176k i'd be concerned about the transmission. Usually they see 200k with marginal to good maintenance, and with proper maintenance can see MANY more miles.
On the flip side, if I were giving advice to the guy selling it, I would tell him to keep the car. Selling a Q45 of this vintage is never a money making proposition. You have to buy an older Q either for salvage parts and throw the rest away, or fix it up properly and keep it forever.
With all that being known, I test drove 3 brand new Infiniti's last week to replace my Q.. I still feel like my 94 Q is a higher quality vehicle than many of the new infiniti's. Sure they have fancier looking interiors and sleeker styling, but truly the driving experience is not the same. The newer infiniti feel nice, but I still feel "at home" in my Q.
While my Q is probably one of the best running Q out there and very reliable, although not super ultra clean, I'd never get 3000 for it..