I was able to check out bikeforums member defixated's swift that he is about to sell. Thanks for letting me take it for a spin and kick the tires so to speak. Compared to the other folders I've seen so far, the Swift feels by far the most like a "real" bike.

Anyway I also measured the dimensions of a Cessna 172 baggage compartment and here's what I came up with:

Width: 29-31 inches depending on where you measure. 29" towards the rear, 31" towards the front but with a narrow section of 29" near the front where there is some extra plastic that protrudes inward.
Height: 31" in the rear, 38" at the front.
Depth: 23" at the bottom. 17" at the top with the rear seats fully upright. With the rear seats leaned forward, there would be 32" of clearance at the top.

Sadly, I must conclude that while I could probably shoehorn the Swift back there, it ultimately isn't the bike for me. This is too bad because I really do like the bike and it's reasonably priced. I guess I only get to pick two out of: folds small, good quality, low price.

Thanks all for the the input, I appreciate it.