As a mechanic I feel your pain, lol. Sounds like the $4500 dollar Mazda SUV I had in Japan (they don't make it here in the states), that ended up costing me an additional 3 grand, and ended up selling for 1700 after I left the island. Majorly bad investment.
But also, being a guy who always believed in the term "machine empathy" myself, vehicles take a little time to learn and become familiar with, like all other machinery. Take this from a guy who has put his hand on a playstation before and made a scratched game CD work perfectly after about a dozen attempts to make it run. I don't know, just one of my "things" I can do. Vehicles have a personality all their own because they were crafted by humans, like any majickal device would be. Until they figure out a way to completely automate the entire process, from scratch (and I mean "everything", like casting the steel parts and assembling every single inch of the engine and drive train), some essential part of every vehicle will be invested with energy. You just have to tap into it and get that thing tuned into you.
With my latest baby, 2000 black and chrome 4WD, manual transmission Tacoma (my dream come true), its been a matter of finding what music she likes. I know you said you need a working stereo. Doesn't have to be a monster, $2000 earth shaker system. Just something to pipe some tunes thru that little girl's body panels and wake her up to you. Vehicles talk, you just gotta listen. And yes, things do go wrong. .....coz its manmade. The craftsmanship is a blessing and a curse. So I'll welcome what pic you may be able to post and feel free to shoot me an email if you want with more details of that baby's probs. I'm serious about this stuff. I know it sounds a little goofy, but I'm good at it.
I'm sure you knew most of this stuff already, but I just wanted to lend a helping voice of advice to you. If I thought my brother there in Cartersville (ASE Certified Master tech) would be willing, I'd send him your way, but he's a jerk when it comes to favors. So I'll do what I can on my end.