My brother in law bought a BMW 5 series that had been in a front smash ( was spun out and hit a concrete wall during the spinning, all hitting on the same front section of the vehicle), and another that had been written off at his work ( brick truck did not quite make the turn in the parking lot, and drove over the rear of the vehicle), towed them to his home and spent 3 months to prepare them for the joining in the middle, just behind the B pillar. Seamed the roof, chassis and brazes the 2 sections together, and then spent time doing a perfect cover up of the join inside, outside and under the vehicle, so that you could not see that it had been 2 separate vehicles. Also took care in the joining to get the wheel base exactly right so it would not crab ( a common fault in making a 2 donor vehicle) and got the alignment correct. He drove that vehicle, which on his mechanic's pay he could never afford at the time, for over a decade more, the only investments he made were buying 2 tons of scrap steel as the price paid for the wrecks, and sold off the rest of the parts that were not used either, to cover almost all of the costs of the paint and such. Good market for accident parts, and 4 good doors were worth a lot, along with good front and rear glass from the vehicles, along with a somewhat dented motor and gearbox from the one, and a damaged differential from the other, as parts for repairing others, as being a current model at the time there was a price premium for them.