Getting a car loan immediately before getting a mortgage is not a great idea. Your credit score will drop a bit and your debt ratio will be higher.
When I obtained a car loan 3 years ago I watched my credit score drop about 40 points to about 740. It took 9 months or a year to get back t where it had been.
If you are still 12 months away, it does not really matter much on your score, but impacts your DTI ratio. If you will be purchasing at low DTI anyway (e.g. 25%), then the only thing to consider is your score.
