No idea where you're located, but if you are within striking distance of one of the upcoming big car shows (there are a bunch of them), I found that an ideal opportunity to make a final decision. I had previously whittled the short list down to the Audi S5 Sportback, the Infiniti Red Sport Q60 Coupe, and the Stinger.
I had already done the test drives I needed, and formed my initial impressions. I then went to the International car show (in Calgary), moved directly from car to car to sit in and refresh/confirm my feelings about the key features, ergonomics, sight lines,
seat comfort, amenities, options, materials, etc. Took a good, long final look around at all the other competitors/possibilities at the show to make sure I wasn't missing anything, and made the final decision that the Stinger was exactly what I wanted.
I started soliciting pricing on the Stinger from a number of dealers the next day, and signed a sales order for the exact car I wanted within the next week. I though I'd be waiting for 3 months on the next boatload, but lucked out and a brand new one (7 kilometers on the clock) rolled in on a transporter literally days later. As the salesman said when he called, 'only driven by a little old Korean man over to the shipyard'.
Zero regrets - I could not be happier with the car.