Remaining Payment on a Used Car Purchase

Hi there peeps,

Just wondering if i could get some advice on here.

My OH have just got her eyes on a nice looking 15 plate hybrid yaris over the weekend and after some bargaining, we managed to drop the price slightly to around 10k with RAC platinum warranty for an extra 300. It's had a damaged wing mirror and some scratches on the bodyworks,the dealer agreed that he'll fix the wing mirror and resolves all the scratches on the bodywork when we pick it up.

(P/S : Is the RAC warranty worth while? I've had a search through old threads, and mostly said its a waste of paper)

Now having taken on advice of credit card protection, they would not accept our credit card at first, but finally budged and accepted our deposit half and half. 250 (+3% surcharge) which i'm happy to pay just the extra 6pound on Credit card, and 250 on our Visa Debit.

Now comes the main issue which is we both work and our only day to try and pick up the car would be a weekend once the works are done (apparently will be done in 4 days) . So we said we'll schedule to come back either on a Sat afternoon or Sun Morning to finalise the deal. The dealer has said we would have to do a bank transfer on Sat morning to them in view of collecting it on Sunday or Sat Afternoon as they will tax the vehicle for us on Sat Morning.

My question is, is it safe to do so? Paying the whole remaining of the money without even inspecting the final state of the car, or should i insist that i would like to pay the balance of the invoice on Sunday/Sat afternoon on my Visa Debit? When i said i could still do internet banking on Sat afternoon, they said it needs to be in banking hours for the funds to clear.

Any great advice would be appreciated please. As its the other half first big purchases, she is kinda worried sick over it.