Welcome to the Sunday edition of the Hooniverse Weekend, with a look at how long certain platforms have been in production. After doing a bit of research, I have discovered that General Motors used existing platforms longer than almost any other domestic car company. But I decided to zero in on these two platforms because they underpin cars that are still being produced (or were just discontinued as of a few months ago).

The W-Body started out as the GM-10 designation when it hit the design phase in 1982. The design was radical at that time, planned as primarily Front Wheel Drive, fully independent suspension, with a number of engine and transmission combinations depending on which division it was used for. The rear suspension pieces were unusual in the fact that they were supported by a transverse fiberglass rear leaf rather than conventional coil springs. Later re-designs of the platform did away with the leaf, and replaced it with a more conventional setup.

In 1988, the new FWD Buick Regal, Oldsmobile Cutlass Supreme, and Pontiac Grand Prix, made their debut. These cars replaced the popular G-Body Coupes (Cutlass Supreme, Grand Prix, Monte Carlo) with mixed results. The 1990 Chevrolet Lumina debuted in the 1990 model year along with the sedan versions of the Grand Prix, Cutlass Supreme, and Regal. The cost to develop the original GM-10 platform was close to $7 Billion! No wonder it’s still in production today, under the venerable Chevrolet Impala. That’s 23 years and counting.

However, the real surprise is the Cadillac K-Body, developed back in 1986 as the newly downsized Seville. This designation was given to seperate the similar platform used under the Cadillac Eldorado, Olds Toronado, and Buick Riviera coupes. Only Cadillac used this platform, which went on to underpin the Cadillac DeVille in 1994, until it was used for the Buick Lucerne that was introduced in 2006.

The Seville retained this platform until its passing in 2004, and the DeVille derived DTS still used it until it was discontinued in May of 2011. This chassis was so flexible that different wheelbases were used over the years, and the suspension received significant upgrades for the 1997 model year, but it was still the same basic chassis and components that were used since 1986. That’s a 25 year production run.