Putting a pool light in the floor might work, until you drop a wrench on the lens. The typical pool light lens is not particularly durable.
Those Tahoe lights are designed for paver-stone walkway accent lighting. The lexan is 1/8" thick. They hold small 12V bulbs and are not going to be capable of throwing anywhere near enough illumination to be worth the trouble, under a lift.
I think you should research higher-wattage, professional architectural landscape lighting fixtures that are made to be placed in concrete walkways, etc...These are typically of cast brass or aluminum construction and are seen very often these days at newer shopping malls, outside movie theaters, etc.
These fixtures typically have very thick block glass lenses and are designed to stand up to foot traffic, etc. and (surprise!) they ain't cheap.
Again, I think in-floor lighting is not going to give you the lighting performance you seek. Most often when working under cars, you need to position the light source up close to where you are working, and often you must put the light source above/on top of or around items that are under the vehicle like the exhaust, suspension, etc, to actually see what you are doing...Lighting in the floor would be blocked by these items, and you will need another light source, anyway.
I think that if in-floor lighting actually worked on a practical basis, we would see it in every professional auto service facility, and...hmm...we don't.
Now, if you want to do it for the "wow" factor, since it will no doubt look nifty, then that's something else entirely. You can get colored bulbs and live it up.