Here's a quick-and-dirty floorplan. Roughly to scale:
The two long rectangles represent cars- approximately 6-1/2 feet wide and 18 feet long, representing a big car or typical pickup truck or even Suburban. The grey rectangles roughly represent workbenches.
The lower section is the main shop, with the garage doors shown in blue (roughly drawn, I know they're two different sizes. ) This portion is 40' deep and 50' wide, for right at 2,000 square feet.
The upper section is another 1,000 square feet, divided into two 20'x 20'/400sf rooms. These are the "clean" and "dirty" rooms- for a guy like me, there'd be machine tools and such in one side, with the grinders and welders in the other side. For a dedicated woodworker, you might have the sanders and planers on one side, and a clean room for glue-ups and assembly on the other.
It could also be metalworking on one side and woodworking on the other, or for a hot-rodder, the cleaning and machinework stuff on one side and the 'clean' assembly room on the other, or whatever.
The middle section is the last 200 square feet, and can hold the bathroom, the furnace and water heater, a utility closet, etc.
It might work better if this portion is set at one corner, and the two bigger rooms are placed side-by-side. Especially if you have something like a woodworking shop with sanding and planing on one side, and glue-ups and assembly on the other- a pass-through door would of course speed up the process. Ditto the hot-rodder; being able to roll a cart with the clean engine block straight through might be better than having to roll it out through the main shop.
But either way, that's 3K square feet. Which is, to be perfectly honest, pretty luxurious. My current "machine room" is just under 400 square feet, and I have two lathes, four mills, three drill presses and a shaper in there, along with two rolling tool chests, two fixed tool chests, and 12 feet of workbench.
If I moved everything into that floorplan, the big lathe would stay out in the main room, and all my welders, saws, grinders and sandblasters would go in the other room, which would leave a huge amount of central workspace for me.
Maybe I should do a Kickstarter... that couldn't cost more than, what, maybe a quarter-million?