Hey, TomKioti, you might want to run that by the folks at Pennzoil... Back in the mid-80s, Pennzoil had a verbal (with handshake) deal to purchase a company. Another (larger) oil company came along and "unhooked" the deal, causing the company they acquired to break their "word". Pennzoil took them to court, and won a TON of money from them - something like $100MM. The judge ruled that a verbal agreement could (and did) constitute a "contract" if it otherwise met the legal definitions.
I remember it well, because one of my best friends' wife worked for Pennzoil, and she got called in to work the night the payment was electronically transferred to them... Seems their accounting system couldn't handle an amount larger than $99,999,999.99, and she had to make a bunch of emergency fixes to allow it to process the payment.
Gee, I wish I had that problem with my bank account!
OK, in the "real world", no dealer is going to try to enforce such a handshake deal, because of the bad publicity it would generate. But they probably could if they really wanted to, and had witnesses.
I guess to me the bigger issue would be the "personal honor" side of it. Once I give my word on something, I don't need a judge to tell me that I need to honor it... Probably my military background...