Start with the basics: maintenance books, condition of cams/vavletrain upon visual inspection via the oil-cap, of course look for matching #'s on panels, and lastly inspect the doorjams/panel edges for paint spray lines. (your fingers will tell you more on that last one...feel for a ridge that wont rub off easily)
If the cams look mirroresque/shiny/clean, the numbers on all the panels match, you can't feel any repaint ridges, and the books are there or mostly there you should be on track. From there, take it to a mechanic whom you trust.
They are a helluva car. Everyone I know who has one loves every minute and mile they spend. Let us know how it turns out.
kills C5's after 120K miles
[This message has been edited by Lee Scheeler (edited 07-24-1999).]