Here's some advice from somebody that actually sees real-life salvage cars every day: Insurance companies are weird. On the subject of 350z's in particular, I've had 2 that did indeed have light damage -- one just needed the front bumper and core support (I think I could've straigtened the core support). Once it got to auction, though, the skilled forklift drivers berkeleyed up the rear bumper cover, and bent up the rockers something awful.
Then, of course, there was the rolled over a couple times in 3 axis' 350z that then caught fire. I think 2 lugnuts and possibly the engine block were good.
If it's a track car I'd be all over a salvage titled car like stink on E36 M3, but pay for the car like it's got a salvage title. No matter what condition it is, it's always going to have a salvage title (unless you live in a state where it's easy to convert or wash the title) and the resale is going to be difficult and nowhere near what a clean title car would be. A track car is going to end up getting run into a wall, or down a culvert, or over a catch fence doing 8 flips in the air... if everything lines up right and there's no huge frame damage, take your discount and run.
Also, you don't have to be a professional to spot frame repairs. If they're E36 M3ty, believe me, you'll notice. If they're not, chances are it was done by a professional... the "professional" may be their skills in cover-up and conning, but they're professional none-the-less.
Joking aside, give the car a good look over or have somebody you trust do it. If the price is right, there's no reason to shy away. Just make sure it's also currently registered, as there's usually a several hundred dollar "bring back to life" charge if it hasn't been done, but it depends on the state.
