Motor vehicle accident – Motor vehicle insurance – Judgment in default entered in favour of Claimant against owner of motor vehicle as well as driver – Court’s refusal of insurer’s application for declaration to avoid policy of insurance – Whether insured should be allowed to employ same defence as used in the application for declaration – Whether issue estoppel or res judicata arises – Whether insurer should be held liable to indemnify Claimant in respect of judgment debt – Motor Vehicles Insurance (Third Party Risks) Act, Section 18(1)