Electric-car maker Tesla Motors (TSLA 3.46%) will finally unveil the production version of its Model X SUV on Tuesday. Up until this point, the company has kept many details about the vehicle on lockdown. Can Tesla live up to high expectations when it finally shows off the vehicle Tuesday night?

Invitation to Model X event. Image source: Tesla Motors.

Ahead of the launch of Tesla's Model X, here are a few quotes from Tesla CEO Elon Musk about the new vehicle for investors to ponder.

Second row seats
Musk has made it very clear that there is something special about the second row seats.

"They are the nicest second-row seats you've ever seen in any car ever," he said during the 2014 fourth-quarter earnings call. They are "a piece of sculptural beauty," he continued.

But Musk also said during the Q4 call the seats have been difficult to get right: "That actually might have been harder than the [falcon wing] door."

This sentiment about how problematic the seats have been continued even into the company's most recent quarterly earnings call.

"[O]ur biggest challenges are with the second row seat, which is, it's an amazing seat, like a sculptural work of art, but a very tricky thing to get right," Musk said during Tesla's second-quarter earnings call.

Was Tesla able to accomplish its vision for the second row without making any compromises?

What else is there to Model X?
One mysterious reference to Model X came during the company's 2014 fourth-quarter earnings call when Musk said there are "other things about the X that people don't know about yet." What was Musk referring to? The CEO went on to say later during the call that these other features are the reason the company planned to keep the vehicle shrouded in mystery until it began deliveries.

Model X prototype. Image source: Tesla Motors.

One new, formidable feature to surface in recent weeks that Tesla hasn't talked about is a seamless piece of glass all the way from the bottom to the windshield to the top edges of where the falcon wing doors begin (which are the rear doors that provide entry to the second-and third-row seats). The feature was shown in photos from the Model X configurator for Signature reservation holders. But are there more unique features Tesla hasn't talked about yet?

And its also worth noting that while its clear Tesla plans for its second-row seats to be special, the specific features that actually make them special are still unclear -- so the seats are probably one of these "other things" as well.

How well will Model X sell?
The biggest question for investors regarding Model X is how many of these vehicles Tesla will be able to sell. Tesla entered 2015 with over 20,000 reservations for Model X. After the X is unveiled, will customers keep their refundable reservations? Even more, will reservations for Model X ramp up?

Tesla plans to deliver its first Model X units during the event. Going forward, Musk has said on several occasions he hopes Model X sales will rival or even surpass Model S sales. But it's going to take time for Tesla to ramp production to meaningful levels. During the company's most recent earnings call, Musk indicated Q4 Tesla is uncertain about its ability to ramp production during the quarter, though he also said he expected production to pick up considerably during Q1.

Tesla's Model X event begins at 7:00 PM PST on Tuesday, September 29. Tesla has confirmed with The Motley Fool there will be a live stream of the event on its website