If you have no credit score it is generally far easier and more affordable to establish credit the cheapest way possible, which is usually in the form of a small credit card (student card if you are a student, low credit line unsecured, or even secured if you need). Your local bank/credit union will usually be keen to offer you something to start out, but you can also apply online to some of the major credit card vendors. As always, look out for annual fees, etc.
In general, trying to get a larger loan to establish credit will cost you a lot as you will not qualify for any legitimate 0% or ultra-low APR car loans - those are reserved for people with established and generally pretty good credit. I expect you'll find a car loan that will have a lower APR than you could get investing your money otherwise - especially if you do not have established excellent credit - to simply be a phantom (you won't find it), and even if you could it is more risky than it is worth.
Furthermore, if establishing credit is important to you (such as for buying a house down the road), you can build an excellent credit score without ever having a car loan. So you don't have to buy a car on borrowed money just to hope to get approved for a house some day - it's just not a requirement.
Finally, I urge you to make a decision on the best car for you in your situation, ignoring the credit score - especially if you are more than 3-5+ years away from buying a house. Everything else about buying a car is more important - the actual cost of the car, year, mileage, suitability for your needs, gas mileage, maintenance and insurance costs, etc.
Then, at the very end of your decision making process, ensure that buying the car would not put you dangerously low on savings by squeezing your emergency fund. Decide if you really need a loan or as expensive of a car, considering the costs over the expected life of you owning the car (or at least the next 2-5 years). Never get trapped into just thinking about monthly payments, which hide the true cost of loans and buying beyond what you can afford to purchase today.