Try Grand Rapids. About 2 hours drive at both ends. SWA flies there.
We’re Detroiting Thurs night late. And then driving a lot. Inara might not find that so fun...and splitting starts makes for some really long days.
Yeah, it took me three whole days to figure out how to make it work. Of course, coming from a different direction from you, so none of what I found out would help you. Luckily, one of my traveling companions was able to get a rental car that we could drop off in a location different from where we picked it up without an additional fee, so we're flying into Chi, driving to South Bend, then to Brighton, and flying back from Det. I had previously thought about flying in and out of South Bend on United and just skipping the Long.
Hope you find something!
I'm doing the same as Dennis. National car rental didn't charge the drop off fee.