Is the wiring thru a hole in the wooden top? Does this machine have a knee controller instead of a foot controller?
If so, detach the knee controller from the side of the cabinet...it is only a couple of screws. Then lifting the head of the machine and laying it sort of on it's back....loosen or unscrew the little pegs that hold the machine in place and lift the machine. DO NOT LOSE THESE SCREWS! they can't be replaced to match up with your cabinet. The repair shop doesn't ususally carry replacement screws for old cabinets.
By removing the screws for the controller first it gives you more leeway to manuvear the machine for putting it in the car.
Then you can transport it the way you wanted.
Sorry to yell, but I used to work for a dealer years ago, and I had calls all the time asking for replacement screws....