According to a Wikipedia article the Tesla Model S is a unique design, not based on some other production car (
Tesla Model S - Wikipedia, the free encyclopedia). Basing it on something else would surely have brought prices down, but that's not a primary concern, apparently. Heck, it's an expensive luxury car, build too many and you lose exclusivity, which I guess is part of what you're paying for. Those of us who can't afford a $60-100K car just take old parts and build our own exclusive ride...
Tesla doesn't build a hybrid, and the big battery pack is rated at 265 miles by the EPA (Tesla says 300 miles...). It takes ONE HOUR to restore only FIVE MILES of range from a typical 110V/12A outlet. From 0 to full charge in only 53 hours. Well, lets' be fair -- you'll never hit zero charge. My best guess is it will run down to 20% at the least. With 20% battery power left it only takes 42 hours to top off from a typical electric outlet. But then I think I could put a 220V outlet in the garage if I had one of these! From a RV type 240V/40A outlet you get 31 miles per hour, or only 7 hours to top off a 20% battery. That's more like it! Just make sure there's a 220V outlet available if you need to stop overnight. I suppose you could stop at an RV park, but who drives a $100K car and packs a tent? Surely you're not going to pull a trailer!
Hey, there's a market for you -- a stylish streamlined teardrop style camper to pull behind your Tesla S on long trips! Can't see it happening. What I can see is a nice little stylish streamlined trailer that has an energy efficient diesel or propane generator. You need just enough power to run the car while cruising. The car battery would be used all the time, just plug the built-in charger to the generator. If the generator will support all electric needs at cruising speed (lowest power consumption) the battery would only be depleted during acceleration and maybe pulling hard hills. That should effectively double the cruising range, especially on a cross country trip with mostly interstate driving. The trailer is a good idea for ANY electric. I've seen a plug-in DIY hybrid that installed the generator in the luggage space of a Geo Metro, but having the generator inside the car is just a bad idea, thought it's rather compact (
DIY Plug-In Hybrid Car -- yeah, it's a kludge!). A trailer or hitch rack would work well, and would be even better if it were wired to charge the batteries directly instead of going through the charger.
I've seriously considered building a simple hybrid from one of my old Ramblers. Relatively light and roomy for batteries. The heavy 196 six weighs around 500# -- batteries wouldn't weigh more, average weight of a 100AH deep-cycle marine battery is 50#, so could run 10 of them with no weight gain (120V -- but you want to run at least 12 for 144V for decent performance). The little Geo in the above link (generator in back) uses a 72V battery pack, has a top speed of 45 mph, and a range of 20 miles on a charge. Range is the biggest problem with home built electrics. Twice the voltage would give an estimated 73 mph top speed with just a little more range, or milk it to get 30-35 miles. Still not enough for me -- I live in a rural area. With the trailer doubling the range (but using some fossil fuel) you'd still get 60+ mpg. The little electric Geo is estimated to get the equivalent of 130 mpg. Or spend $1300 each on 10-12 Lithium Ion batteries that weigh a lot less (28# instead of 50#, plus they will run a bit longer than a lead-acid battery. L-I batteries are what the Tesla uses, though not car battery drop-in types (
12v 100ah sealed lithium ion battery marine). Battery cost is the main problem with ANY electric -- the cost of batteries that have dense enough energy storage to be practical. A 40-50 mile range would be a minimum to me, and few home builts can do that and still have (barely!) adequate performance. The 45 mph Geo is barely adequate for around town to my way of thinking!! Speed of 55 minimum along with a 50 mile range would be barely acceptable as a second car used in town only. Tesla performance is more like it!!