Here is my take. If i want to buy something, I'll give you a deposit and we'll draw up a purchase agreement. It will state the purchase price, the deposit, and the terms of how long the car will be held for. This way, there are no questions. If I'm selling, I do the same. This takes out all the possible confusion over a deal. From a seller's standpoint, I cant tell you how many times I've held a car or part for someone without a deposit, and they never come thru with the $$. So unless i know you personally, I'm getting a deposit and we're signing a sales agreement, or the part/car is available until i see the $$. Now if I'm buying something, and the seller wont take a deposit, I'll be darn sure he/she gets the $$ as soon as i can arrange it, no BS.
I put a deposit on a 71 Roadrunner at Carlisle 3 years ago. $1K deposit, balance due ($16,000) within the week. Wrote up an agreement, guy was from florida and a licensed car dealer. He was supposed to store the car in a storage place in carlisle and send me the key to it when I gave him the $$. After i tried for 3 days to get ahold of him starting Monday after carlisle, i finally got him on the cell and in the next several weeks got all kinds of BS stories about what was going on. Finally, I paid $20 to an internet search company and got his home phone number and address. Called him there, got his wife , told her what was going on and let her know if i did not see my deposit money back in the next 3 days, i was calling the Florida state attorney general's office. Got my check within 2 days. about 2 months later, that car came up for sale in new york...called the seller and it turns out he paid 19K for it at carlisle about 2 hrs after i had put my deposit down. So much for the agreement, it's only as good as the person's word. It will give you some proof in court if you end up there.
Now I've dealt with a guy on several Mopar deals, if we agree to something, we're good. No paper, etc. If i ask him about something on the car, he'll tell me if he knows the answer, no BS. But thats an exception in this day and age, sorry to say.