How to request a settlement figure
Contact your lender in writing (email or their online portal works) and ask for a "section 94 settlement figure". They must provide it within 12 working days. It's valid for 28 days from the date issued.
How much you should save
The lender is legally allowed to charge you interest up to the settlement date plus (on agreements over £8k) a small early-settlement fee — typically 1-2 months' interest. Anything more than that is not permitted under the Early Settlement Regulations.
When it makes sense
You have surplus cash and want to be debt-free. Interest rates on your savings are much lower than the APR on the finance. You're selling the car privately and need to clear the finance to transfer ownership.
When it doesn't
You're using an emergency fund to do it, or you're within 6 months of the natural end of the agreement (savings usually negligible), or your APR is 0% (no interest to save).