Hi Johnno,
The finance company can collect both cars if they wish but I have found in practice that they would prefer to receive the monthly repayments, particularly on the older car! Speak to someone higher up the food chain at the finance company before you go BR. You can put HP payments in your income and expenditure statement and try and persuade the OR to accept them. All should be fine for the older car, I'm sure, if you play it right.
However, before you go BR, you might want to tell your insurers as well since they have similar t&c's regarding BR and you could be uninsured after your Court appearance!!
Best of luck.
Steve