SAN FRANCISCO (MarketWatch) -- A prototype of Tesla Motors Inc TSLA, +4.42% next model, the Model X, will likely be unveiled at the Detroit auto show, analyts at Goldman Sachs said in a note Friday. The analysts visited the factory in Fremont, Calif. recently but didn't get to see the prototype of the SUV. The car will have a dual motor all-wheel drive feature, which points to "a superior driving experience for owners," but will add about $1,200 to the price, Goldman said. The Detroit auto show takes place in late January, with previews for the press starting Jan. 12.