I recently sold my car to a garage/dealer. They looked at the car, test drove it and gave me money in cash. I have a receipt signed by both sides.

The carte gris was cancelled. The plaques returned.

Later, they called up to say they couldn't sell it because the car doesn't have the service record book which they hadn't asked for before the sale- and I have misplaced.

Can the buyer ask for the money back? Is there any 30 day return law? Do you have to give the service book for sale of a car?

I shouldn't think so. They paid you the full amount?

What's caveat emptor in Swiss German?

No.

There is no service book here.

Tom

What a bunch of amateurs. A garage is supposed to be an expert buyer.

Always include the the line "sold as seen" in all private sales and before signing the selling contract.

Doesn't always necessarily preclude you from come-backs.

Sure they can ask. I doubt you need our help with the appropriate response from you.

Oh, come on. Let’s hear what you would say.

There is no requirement to ever service a car.

caveat emptor

how old was the car? did you ever get it serviced (I'm guessing not) etc

all main dealers and most indies keep all the servicing records on computer so its simple to get a copy.

as for the garage, lol, tell them to do one.

Any decent brand should have this maintained electronically.
Perhaps you could ask at one of your former service spots for a printout?
(I can literally get a PDF out of a mobile app for my car)

Nice first post (again). How does one go about misplacing a car's service book exactly??

You sold the car, they bought and paid for it.
Ownership has now passed to them.
Had they asked for the service book as a condition of purchase and you had not provided it, then it's a different matter.
If this was not the case, then they have no recourse to you.

You replace it with a big stack of receipts from when each service was done. Or you realise that the value of the car is now less as it has an undocumented past. I don't know many OEM's that will supply a new book.

Selber schuld

You can buy replacement books very easily. It's the stamps that are hard to recreate, although if all of the servicing has been done by the same garage and they have records, they might recreate it for you.

The return period according the law is 0 days, 0 hours, 0 seconds.
You have to provide the booklet if the booklet was part of the sales agreement. If you sold the car as is (ab Platz) then it is their problem. They had time and opportunity to check at time of the sale. Everything not handed over there and then (and not mentioned otherwise) was not part of the deal.

Or in other words: Read your sale contract.

If the booklet is part of the sale and you are unable to produce it than they have different options including cancelling the sale or negotiating a refund.

__________________
"Okay, I just hope we don't wake up on Mars or something surrounded by millions of little squashy guys."

I would suppose this is the OP's statement that this service book wasn't a condition of the sale, and wasn't mentioned at all either directly or indirectly e.g. "do you have a service history?"