Thanks for the comments, guys.
The deal is done and I brought it home last night... a 150 mile trip from the dealership... and didn't have a single complaint. Feels great to be a Bonneville owner once again.
I can't believe the shape this car is in... other than a missing cig lighter, I couldn't find a single fault with the car. It'* a two-owner car and has been registered in the same area since new. She'* fully loaded, complete with OnStar and the factory CD changer (that still works!). Almost seemed too good to be true so I took it to the local Pontiac dealer to get checked out before I bought it and it turned out that very dealer sold it back in 2002 to the 2nd owner and she'* had it serviced there for the last 7 years, so I got to see what had (or hadn't) been done. Jackpot!
Will spend the next few days getting acquainted with it, but so far it looks to be a good solid ride.