username123 - Wow, I didn't realise a car loan would be around 15% interest rate. It's over 10 years since I had my only car loan so I wasn't really up to speed and didn't really look into it. What you suggest makes sense especially if we have the ability to change our repayments on a regular basis.
Brendan - I think this pretty much makes our decision to pay a higher deposit to keep the LTV ratio less than 50% for the more favourable interest rate. I think we might start our monthly repayments at €1,000 rather than €1,300 initially to build back up our savings and buy a car without a loan. The minimum monthly repayment would be around €560 so we are still overpaying quite a bit. Once we get the car and if we are happy with our financial situation, I think we will up it to around €1,350 to help clear our mortgage in about 10 years.
Thanks to all who have offered advice here. Much appreciated.