Using Credit Card to Purchase Car

I’m looking to use my Barclaycard Rewards credit card to purchase a £10,000 car with my credit limit being £11,000. I have the money available to make the purchase using a bank transfer or debit card however I thought it would be worth while using the credit card as I will get some sort of cashback on it.

My mortgage is due for renewal this November and I’m just worried that if I spend £10,000 on a credit card (but then pay off the full balance once the statement is issued) will have a negative impact on my credit score?

Just to confirm the dealership have stated that they do accept Mastercard and VISA credit cards.

Thanks in advance.