If you are unsure or lack the time like most people then use a good car finance broker. Make sure they are established broker and check to which car finance companies they use.
Compare Car Finance Interest Rates
When using a car finance broker get them to compare car finance interest rates. You can use a online car finance calculator to calculate different car loan repayments. Check to see what finance companies and bank car loans they have available.
You should never be approved on the condition that you have to purchase a certain car or car yard. These types of loans normally come with interest free loans. As the saying goes, nothing is for free. Normally this is offered offered because you pay thousands to much for the car you are buying.