Musk mostly mum on details about the falcon-winged X Jeremy C. Owens/MarketWatchDetails about the Model X, shown here at its launch, were sparse on a Tesla callTesla Motors Inc. shares rallied on Wednesday following quarterly results that were better than many on Wall Street had expected, but the electric-car maker is still playing it close to the vest when it comes to its newly launched SUV, the Model X. Analysts peppered Tesla TSLA, +0.06% with questions about the Model X during its conference call after the results, but details were sparse. To those keeping score, here are three things we still don’t know about the falcon-winged car: How much it will cost Demand for the X is not a problem, Tesla Chief Executive Elon Musk said at several points during the call. He was less forthcoming about how much it will cost, however. Instead, Musk stuck with what he has said before: Model X trims will sell for $5,000 more than a comparable Model S trim. The Model S starts at $75,000, and comes with a 70 kilowatt/hour battery. A middle-of-the-road version, with an 85 kilowatt/hour battery, sells for $85,000. The top-of-the-line S, the P85D, starts at $105,000, plus $10,000 to get the “ludicrous speed” upgrade. So far, the only certainty is that the fully loaded, “signature” series Model X starts at $132,000 before any upgrades.What trims will be available Tesla has talked about a lower-spec Model X, but the suite of Xs to be offered is unknown. The Signature cars come with a 90 kilowatt/hour battery and are able to go 240 miles between charges, seven miles more than a Model S P85D. It is unclear whether Tesla will follow its Model S offerings and put out three trims for the Model X.How and when production will ramp up The main thing with the S is “just scaling up production,” and there are no major issues with making it, Musk said time and time again on the call. But he stopped short of saying exactly how many Xs Tesla will produce at any given time later this year and next year. X’s production is making “steady progress” and it has now come down to the little things, such as door seals, he said. It’s hard to make more precise predictions, however, because the constraints change from day to day, he said. Tesla will be producing “several hundred” Model Xs by the end of the year, and is targeting the production of 1,600 to 1,800 vehicles a week by early 2016. The company brought production of X’s second-row seats in-house to sidestep some of the constraints. More from MarketWatch