[Closed] Adjusting dimensions and/or bounding box

Ok, I think the following problem shouldn’t be to hard to understand.
Imagine this: I merge a car (1 whole mesh, all parts like bumpers, windows attached to each other) into my scene.
But let’s say I am not satisfied with it’s measurements. Let’s say it needs to be scaled a little bit smaller/bigger. Now, I could do this by simply using the scale-tool. But it needs to be accurate. So I could make a box (lengt=5, width=2, and height=1 (meters)), center the car in XYZ into the center of the box and scale it until I am satisfied. Right?

Wrong!
This takes too long (yes I am lazy ). Why can’t I simply click first the car, and then my “target”? So that my first object (car) simply copies the dimensions of my target (box).
It’s almost like the align tool: you align 1 object to another! Isn’t there a plugin that does almost the same with the size of an object? Offcourse I looked around in Max, but couldn’t find anything.

Any help would be appreciated! Thanx.