Impounding UK registered car whilst out of the country

Just wondered if anybody has come across this one before.

Basically, we drove to Morocco from the UK a few weeks ago and am living here for an unspecified time but I had to go back to London urgently ... or so I hoped.

I arrived at the airport, my wife dropped me off in the UK reg car and I checked in as normal. All fine until passport control when the guy said I needed a stamp for the car..?

OK so I went to the customs desk and the guy said I had to have the car impounded until I returned, handing over the keys etc - even though I explained my wife was staying and driving it etc...so a load of panic and my wife returned but they would not let her in to deal with this whilst I got on the flight ... so I missed the flight basically.

Apparently this is the Law and even though my wife was here with the car, it has to be impounded - and if she needs to go back to the UK ... the same applies. She can hire a car or get a taxi ... that was the advice given..

Now I intend to drive the car back in January, leaving my wife here and then return on the next available flight from the UK ... will I get similar issues?

Any help or guidance would be appreciated - anybody come across this before?