Blackhorse Loan Outstanding

MrsTinks

Not at all unlikely - if they find the car they can and will repossess it.
Practical information:
When you contact them then yes they will probably demand payment in full or tell you they have sold the debt on.
The good news is that they can't have what you can't pay but once they know where you are they may come and collect the car if you still have it and chase you for the remainder of the money after they sell it at auction (minus any costs and fee's). However if you are making genuine attempts to repay the debt they will probably realise that they are more likely to get somewhere by agreeing to a repayment plan.
IF they were to go to court then they would be applying for a CCJ - if that happens make sure you go along and show that you can afford £x a month and no more, the judge should set your monthly repayments at this. So long as you meet your CCJ payments then they won't be sending in bailiffs or putting charges on your property or attachments of earnings.