Clean retail is if you were buying a Tesla at a normal car dealer, like a BMW or Mercedes Dealer. Those dealers know to do the basic stuff like clean the stains off the seats and make the scratches less obvious. They might even touch up the wheels. If the car isn't a fit for their lot, then they sell it at auction or sell it to a local "used car only" dealership. The BMW /Mercedes dealer wants all their cars to look pristine so they can maintain their squeaky clean reputation. So if you walk into a BMW Dealership and walk up to a used 2014 7 series sedan you wouldn't expect to be able to see curb rash while standing up, if you get down on the ground you might see it. You wouldn't expect to see any dents, as they would have had their paintless dent guy work the car over. They would do the bare minimum to make the paint look good from a few feet away. Brake pads, oil, and tires are reasonably fresh. This would be clean retail. You buy it and drive away thinking, "this car needs nothing".
They don't normally do the major service though like an annual, timing belt or whatever, unless it can be covered by warranty. Those sorts of cars go to some lower end dealer unless there is a huge up side for them.
When I was saying Clean Retail + CPO I was saying Clean Retail = 45K and then +3K for it being a CPO, to get to a asking price of $48K. Some valuation tools will show a CPO adjustment, some don't, but generally $2k to $3k is how they value it. As the end users CPO warranties could be worth more or less, that is about your appetite for risk and so forth.
Salvage/Rebuilt titled cars can be reinspected by Tesla, but very few are. It isn't a good idea without the reinspection unless you are a VERY serious do it yourselfer plus other risks, if you find yourself thinking about that reconsider a few times
On your quest to find the perfect car, look out for used cars that are one owner and under 4 years 50K. That owner can buy the ESA package and then transfer it to you. It is possible you could buy the car and then buy the ESA after the fact, but check around before counting on that. The ESA isn't as good as a warranty like the CPO or new car, but it covers you from some of the big ticket items. I would encourage you to review the ESA agreement before you actually go down this path to see what is and is not covered. The ESA can be purchased up to 1 month and 1000 miles after the warranty expires. If it is past that, then there are no further options I know of. If the car is not one owner it still might be possible, however Tesla has limitations on the car ever being in a non Tesla Dealer possession. There are good threads on ESA, I am just trying to cover the highlights here.
Also I like cargurus as they allow you to search specific versions like 85D where most used car sites are useless at that. As you are on a quest you will likely have to use all the tools, but on a positive note you live in a place with MANY Tesla's. I came fairly close to buying cheaper white one private party out there and driving it home. I had a route picked out and a plan to sleep on various couches to keep costs down even.
