Hmmm. I always looked at it as exposure to the elements just sitting on the lot and receiving a vehicle that many people potentially sat in and drove it before me.
I don't buy cars with >100 miles on them, they usually have less than 30. As for exposure, well, it's a car and built for it - most cars are not like Tesla where parts fail due exposure to oxygen and humidity (in this case I'm talking about the large screen in S/X which yellows when exposed to non-showroom conditions).
Trading in often loses more value than depreciation over that couple month waiting period. You can sell to vroom and the offer is good for I think a week.
I'm sorry, but I lost you there. No car appreciates over time (Elon's nonsense comments about appreciating Tesla's aside). Private party or trade-in, if you have to wait 2 months before selling, you lose money. As for trade-in vs. private party, you lose the sales tax credit, which is 10% in where I live (so trading in for $50K is the same as selling private party for $55K). In MI where you are google says it's 6% is limited to $5K, but it's still not negligible money. As for how depreciation can hit you, when I was buying my 2015 MS, I had the 2013 trade in. Tesla gave me an offer valid for 7 days but the new car would not be there for 8-12 weeks. 2 months later when the new car showed up, Tesla trade-in estimate went down by $10K, so $11K less in my pocket! If you are like Elon, and have a stable of cars to drive so you have something to drive if your new car arrives in a while (or if your car is stuck in service), this model works. When you're not Elon, and $11K is not pocket change to you, this model is less than ideal.
A 5k discount at this dealer would probably be worth your effort then.
If I wait a bit I'll get it here too. Main issue for me is I prefer the sedan ride (MS ruined me on that front, I didn't even buy the MX I was waiting for since 2013). Etron GT is coming, as is Taycan, we'll see if I hold out or cave in.
But I do agree that many people do like to drive off with one same day. And I feel that way too for a cheaper item I just want to get and go. For a much higher priced item, I prefer to order and get exactly what I want.
I usually don't have a problem getting what I want. There usually is a car in the configuration at one of the dealers within driving distance to me (I usually find the car first, then go to that dealer). Notice that Tesla no longer offers 100K possible combinations either, they are settling on just few option packages to choose from. I bought many cars in my life, only ever ordered 2 - Toyota 4Runner and Porsche 911C4 - first one was not in production yet so I pre-ordered, the latter there was no new cars in stock anywhere and a 6+ month wait list. In both cases by the way the dealer was able to predict and guarantee trade-in value 6-9 months ahead (with provisions of no accidents and no more than X miles driven).
