Who cares? That is the dealers problem
This dealer did you a favour. You got a really good deal because your family and this dealer have history and loyalty.
Instead, you screwed them rather than returning the favour by at least giving them the car in the condition you'd want to receive one in yourself.
You'd have been right back to them if the new car came with a buckled wheel or something, wouldnt you?
And dont give me the whole 'It was going right to another dealer' thing - the transaction was between you and the dealer you apparently have 'loyalty' to. The fact they then sold it on is immaterial - you've no idea how much got knocked off the agreed price once the other dealer realised it had 4 crap tyres, a buckled wheel and was missing a key.
It just smacks of a completely **** thing to do.
And thats aside from the inherent dodgyness of retaining, deliberately, the key to something you are selling. Irrespective of what you then intend to do with it.
But you cant see this - you never will. Its just how you are. You think all of this stuff is acceptable in the same way you think saying 'Sorry mate, your problem not mine' is acceptable if you damage the car of a paying customer.
It's just how you seem to be.
And it's a real shame.
So now its changed from "You still have a key for a car that isn't yours" to "the buyer might be nervous". LOL, if you're going to bitch at least be consistent like you used to and just drop from conversation when you're proven wrong.
I'm still consistent - I'm still standing by 'You still have/had/whatever a key for a car that isn't yours'.