There’s a saying that in a down economy, the first things to go are the toys. It's especially apparent at auto auctions, where in years gone by, perfectly restored and custom American Iron has gone for well into the millions of dollars. Only two years ago, Carrol Shelby sold one of his personal Cobras for a whopping 5 million!

Those days, however, are in the past.

A car is worth basically what someone will pay for it… and lately buyers are paying less and less. As the reknowned Barrett-Jackson Auto Auction begins this week, representatives have modified the inventory to reflect this downward trend. Many cars will be auctioned at mid-level prices and there will be few, if any, seven figure sales.

One extremely noteworthy car to be auctioned off is the first ever production Thunderbird. Yep, car #01 off the Ford production line in Michigan… the 1955 T-bird roadster. After 50+ years, Ford is selling the car. The exact reason, be it the economy or just a clearance of inventory, may never be known. But it is just another sign of the landscape changing in the automotive world.

Other cars of note up for auction this week:

1. For the first time ever, GM is selling many of their concept vehicles… again, a sign of the times? These vehicles have never been made available to the public in auction or any form.

2. Not a first, but another cool GM auction is that of the VIN #100001 for the first regular retail production-built unit of Chevy's 21st Century Sports Car, the 2010 Camaro. The winning bidder will not only receive the keys to this first Camaro, but also the ability to spec and order their Camaro to their liking, choosing from several colors, V6 or V8 engines, a manual or automatic transmission, and various trim packages and free-flow options, all to be built on the first day of retail production scheduled for early 2009. Last year, the 2009 Corvette ZR1 under a similar auction went for a cool million. What will this year's rights bring?

3. A Superbird designed to replicate the vehicle's iconic looks and recreate the original's NASCAR heritage, including the 800-horsepower race-spec 358 cubic-inch V8 engine. However, this monster is said to be completely street legal!

4. Winning NASCAR stock cars driven by Dale Earnhardt Sr. and Jeff Gordon… just to name a couple other big gets.