in The late 80s and early 90s I worked as a car stereo installer. Of course we did much more than audio accessories, radar detectors, alarms, lights etc. One of the biggest things at the time were L.E.Ds, Light Emitting Diodes. They are less fragile than incandescent bulbs and draw a lot less electricity, which is why they worked well to let people know the alarm was armed. They then started appearing in rear spoilers as third brake lights. Now they are replacing headlights and running lights in new vehicles. I wanted a set to replace my headlights because they are difficult to find replacements for ,The plug, which on normal headlights is U shaped. One prong for ground, one prong for low beams and the third for high beams. Well on the '94 S10 they are not U-shaped, one skews off at an odd angle. I checked on line for L.E.D versions of the Sylvania H4666 headlamps, and they ran about $259.00 apiece. I certainly wasn't going to fork over Five hundred bucks for headlights, so I ceased my search. The radio station I listen to is publicly funded, and if I order things from Amazon.com they get a share. So I checked their website for L.E.D bulbs and found a pair for about $39.95. They arrived but the prongs were the typical U-shaped arrangement, so I sent them back. Only after the return was finalized, did I learn there are adapters to use the lamps with the S10 configuration. So I reordered along with the adapters. The adapters came from a different manufacturer, so they arrived much later than the headlights, but once I got them in I was quite pleased with the results. The adapters are a bit bulky, so they had to be coerced into position, but there is enough room to shove them in. So if you are indeed considering the conversion to L.E.D technology, Amazon.com does offer affordable options.