My work is exactly 4.6 miles away, but I still manage to drive about 350-370 miles a week. Not sure how that happens.
My workshop is across the yard from my house, I do about 25K miles per year. I think I must enjoy driving the car.
I can't figure the math here; you own a car and want to sell it and buy a different car, because you want to... save money on... no that's not it. You want to spend the extra money (take bath on current car, pay new off the lot surcharge for new car) in order to... no, because you won't really save... hmm. Nope, just not getting it.
Oh wait, I see it, you really wanted a Wrangler (for whatever reason) but felt you needed something more economical and were willing to settle for the Sonic to save on gas money. Now that the gas money isn't a consideration, you're willing to blow the extra thousands to swap. OK I guess I can see that, except that it's hard to figure out why you got the Sonic in the first place, gas really isn't all that expensive, not enough to prevent you just driving what you want, unless your commute was... hundreds of miles per day?
Anyway, to address the issue, how about listing the Sonic with it's mods, and if someone says no they want it stock, say you have all the original parts and can put them back on. Simple enough for everything but an exhaust system... but why do it when it's likely the mods will actually boost the selling price a little.
Taking off mods and then trying to sell used mods for enough to cover the combination of shipping plus the bother of removing them and packaging them up, doesn't really seem like a very worthwhile venture.