I'd say $2000 at best. The CD player, window, and cladding crack problems plus the looming 100K maintenance knock several thousand off the price. To me it really doesn't make sense to sell it given how little it's worth, I would just hold onto it.
Okay now that's what you tell your wife. In reality it's a really nice VX, and I could see you getting at least $7500 for it if you're willing to wait for the right private party buyer. You may struggle to get half that on trade-in (something your wife may want to consider if she's pushing you to dump it for that Subie).