1999 NUANCES: REFINEMENTS INCLUDE NEW V-6 ENGINES, SEAT MASSAGES, SIDE AIRBAGS.(new technological features of 1999 automobile models)(Industry Overview)

Evolution, not revolution, best describes the technical changes automakers are making to their cars for 1999.

The gadget parade this year will pass largely unnoticed by drivers unless they are involved in a bad crash or spend an afternoon pulling their engine apart. But dealers struggling to devise a sales pitch for something that cannot be seen or touched can take comfort: Though these refinements are under the skin, they help make 1999 cars smoother, safer and plusher.

That much buyers certainly will notice.

Engines of change

General Motors will equip the 1999 Oldsmobile Intrigue with the first double-overhead-camshaft V-6 that is a serious challenge to Japanese competitors. In terms of refinement and technical credentials, this all-aluminum, 3.5-liter, 24-valve V-6 dwarfs GM's previous effort, the 3.4-liter Dual Twin Cam V-6 available from 1991-97 in Chevrolet Lumina/Monte Carlo Z34 and Pontiac Grand Prix GTP models.

The new, 90-degree …