1. Keeping the wheelbase the same as the Model S while reducing overall size is indeed the most economical path.
No it isn't. They are completely different vehicles. That has been the intent all along. The BMW 3-Series, 5-Series, and 7-Series were essentially the same car for decades. And they still didn't keep the same wheelbase. The Honda Accord began life as a stretched wheelbase Civic. Much the same is true of older versions of Nissan Maxima, Altima/Stanza, and Sentra. Within product lines, designs and components have been shared among siblings for decades. The primary distinction between them was generally size, and that was determined by extending, or shortening, the wheelbase to produce new products. NOT by using the same wheelbase on everything.
2. It's almost impossible to estimate any dimensions in this manner, and especially overall length is flat out impossible. The *only* dimension you might get close to is wheelbase but everything else will come out dramatically shorter than expected. There's three factors in that which almost no-one is bringing up:
Except that I'm pretty sure someone, in this discussion, or elsewhere on these forums, or certainly on the Tesla Motors Forum
HAS mentioned them...
A. Linear perspective foreshortening:...
Yadda, yadda, yadda... Most of us know we don't live in a perfectly orthographic world. So,
'DUH.'
B. Curved perspective foreshortening:...
And that is precisely why the world
'perspective' was invented.
C. Camera lens distortion:...
Yes. And that's why I have to lie down on the ground to have a chance of photographing an entire tree that my own eyes can see in its entirety while I'm standing. Understood.
The video comparison shots are probably the most informative, but even with those... unless the tires closest to us followed EXACTLY the same path to the millimeter, perspective effects mean the wheelbase could appear longer or shorter. If the car is dramatically narrower as many are suggesting, then if the cars followed the exact same centerline path, the Model 3 would appear shorter than the Model S just by virtue of the perspective effects against the differences in the vehicle widths. The "few inches shorter" could easily be explained by perspective and those shots could very well actually prove they have the same exact wheelbase.
Given the available information and sources it is pretty well understood that most of what we have gone over here is somewhere between speculation and guesstimation. That's OK. This is a public forum on the internet. Not a US Senate Subcommittee Hearing. Chillax, Man...
Oh, but you are entirely wrong about the wheelbase thing. There is no way the Model ☰ has the same wheelbase as the Model S. When I was a kid and my Mom would decide to change the furniture around, I was her work mule. She'd say,
"Put the couch over there." I'd say,
"It won't fit!" She'd say,
"I wanna see it!" So I'd move the couch, and it wouldn't fit, and she'd see it didn't fit, and she'd ask me to move it somewhere else.
I know what optical illusions are... They typically don't work on me. I have to purposely put my eyes out of focus to get even an inkling of what fascinates others so much. As an artist, I have a good eye for detail and a strong understanding of spatial placement. Even an in-camera forced perspective shot is typically pretty obvious to me. There's always something that gives it away. So I always have to keep my mouth shut around magicians too, because I see what they do and would give it away otherwise. Thus, I automatically adjust for the issues you bring up when I look at photos of Model ☰ next to its siblings Model S and Model X, and I'm sure I'm not the only one capable of the feat.