The Fanntasticar is a various flying hovercraft used by the Fantastic Four, most versions are able to split into four smaller vehicles.
Ikran's Fantastic 4 OC series[]
It was indeed first seen when Reed summoned it from his lab in the Baxter Building via keypad; it was first seen covered in a lage sheet and he preventnted Johnny from taking a peek.
Reed said "it should be here by now!" as the team headed up to the roof of the Soviet prison. Then the FantastiCar shown up! Reed offered to be the main pilot and Terri quieted a commotion between Johnny and Ben saying, if he makes it, he flies it! Simple as that! So the craft chased after Victor who stole the Silver Surfer's board, then the cockpits split into three (with Sue and Norrin in one, Reed and Terri in the second, and Ben in the third! It was shot down by Victor's Power Cosmic as they were stranded in Shanghai!
By the time they had their Chinese wedding, with the world saved by Norrin, Reed and the group, along with Terri and John, ran to the rebuilt car! As each cockpit created the 4 logo before leaving!
It was used again during the salvage mission looking for Shalla-Bal, though it was mostly docked in the Zenn-La mothership. During the missions, the Zenn-Lavians used their advanced ingenuity to upgrade the Fantasticar and make it soar into space! Reed wasn't able to do that before, until their final destination as it aided Terri's AstroWing in the Magik Domain! They managed to retrieve Shalla-Bal's body in a capsule and barely escaped from the black hole by Norrin and the mothership's tractor beam!
It was implied in The Search of the Four that Reed confiscated parts of the sorceress's ship as parts creating the Fantasticar.