One other point Dave after your last post. Although an attached garage is super convient it also will increase your insurance rates over a detached garage. Well, that is true in Ohio? Reasoning is logical, the spread of fire to the house, and also carbon monoxide gas from the cars. Actually if your somewhat handy in framing carpentry once the foundation is completed you can buy a garage package from lumber yards for $7,000-$10,000, these are complete with shingles, siding, doors, etc. but they will not include your concrete floor, electrical, or plumbing.
I agree with MEK, put up a three or four stall garage and let him pay for it in storage rent.