** It's called a yo-yo deal and it happens more often than you'd think. Usually because the paperwork gets signed on a weekend and then they can't find a bank willing to finance the deal at the given terms. And it's pretty likely that your trade-in is already gone. You're lucky that you had finalized paperwork. A lot of times the paperwork states it's "pending approval." **
I thought about trying to contact the Actual Owner of the Naughty dealership, but on reflection , figured although he would say nice and apologetic things to me, his loyalty would be to the GenMgr as I imagine the owner hired him.
I had "Special Ordered" my trade-in vehicle of that previous story - from same manufacturer 8 years prior [ but Different dealership ] - and it was very smooth, positive, experience.
Put down $2K , went thru the exact options i wanted, no more no less, Colors, engine, differential, etc. at Edmunds invoice plus $600. This was back in 2003 when invoice pricing was not so prevalent. It helped that i knew all the codes [ from Edmunds] for each option i wanted. Had financing for the balance lined up already thru credit union. Waited i think 6 weeks or less. Dealeership called me the day it arrived. Saw it come off the transporter, Drove it home an hour or less later.
On the Subaru we have it was special ordered, although like RWD's experience they first tried to push us to a similar XT turboed version but in the wrong color they had on the lot. But wife was firm on color as it was 1-2yr offering, and the bodystyle was changing afterr that model year. There was a similar one at another dealer, right color but missiing options [ turbo gage, and rear hatch spoiler,etc ] - they offered to "dealer swap" for and get that one and have their lot+mechanic guys put on the options, but i said no, ,i want the guys at the factory who do this all day and have the templates to install them. { didn't need leaky hatch/ leaky vacuum in the future} Got a fair deal on her trade-in, which we brought back with normal accumulated miles when the Subaru arrived. Left a good deposit. Waited about 6 weeks. Had financing lined up through credit-union/ bank first, and declined to hear their financing offers pretty much - I think this is key to a good experience - a shorter dealer experience timewise - and one with less pitfalls.
On VW - Tried to special order a vehicle, offered a sizeable deposit. - they said yes, you [ +we dealership XZX ] can try, but basically you will ask for say 4 major options or packages, in an certain color + drivetrain. What arrives will have the color and drivetrain you wanted and 3 of the 4 requested options, no telling which 3....and "i'm telling you before we start, it will be at full MSRP, or the owner won't approve it" . And the sales mgr that day said he could only think of one special order they had done in the last 2 or so years. Which was a Touraeg , with the v-10 diesel, and a whole lot of options at full boat pricing. I wasn't willing to pay MSRP so ended that purchase attempt.
So 2 good new car buying dealer stories - because we were firm on terms, 1 bad story, and 1 neutral cause there was no actual sale- just an inquiry.