Establishing a relationship with your bank is very important when it comes to credit. Your bank can pull up instant information on your profile that outside banks cant. This might allow your bank to approve an application for credit, where outside banks might decline. This is ultra important when applying for a car loan at a dealership. Their are some major banks that dealers have a partnership with. This partnership becomes very important when you apply for a car loan. The process can go from difficult to simple based on relationship with your bank. For instance, if you apply for a loan at a car dealership that has a relationship with your particular bank, and your credit with your particular bank is solid, yet you have a couple slip ups with others, the dealership might still approve you. See, your bank can pull up information like account balance, income, time on job, address, your monthly commitments. Outside banks will not have access to this information and have to rely on the application for this. We have seen many clients get declined at outside banks with shaky credit, yet they get approved if we use their own bank to apply with. When this happens, the interest rate is usually more aggressive and lower than applying at their own branch. Their are also times we can get certain conditions removed(proof of income), where their branch may not. This would allow the process to be more streamlined. In my opinion, it would be wise to open an account at one particular branch(bank) and stay with that one account. Build the relationship with that particular bank and lean on the for the products they offer.
Just my 2 Cents