The first thing to establish is how the car was purchased, was it a Bill of sale, which is the most likely in which case the goods would remain in your possession and use but ownership is not transferred to the creditor so goods can be repossessed. A bill of sale gives the creditor all the advantages of an HP/conditional sale agreement and removes some of the disadvantages; the creditor with a correctly executed bill of sale can repossess the vehicle without a court order so I am puzzled by your reference to court action
Where the bill of sale secures an agreement regulated by the consumer credit act there must be a separate agreement, which complies with the CCA. Enforcement of the agreement includes the exercise of the creditor under the bill of sale, and if you have reduced your payments without the agreement of the creditor this may be the difficulty.
As has been said the key to this will probably be discussion with the creditor, which I would suggest, you deal with immediately.