It doesn't matter if you're purchasing a new or used vehicle, it makes sense to research beforehand and not only research the vehicle but also the financing and products offered. Products offered can include extended service contracts (often referred to as warranties), credit insurance, glass-etching, pre-paid maintenance, and much else.
Previous news articles here have described how the price of vehicles is increasing, how monthly payments are increasing, and how the number of months to make those payments is unbelievably long. It's all true.
A study by MakeMyDeal in 2015 reported:
Currently, most consumers are first exposed to F & I offerings after the vehicle price and trade-in have been negotiated at the dealership, but the study shows that consumers would prefer to learn about F & I products beforehand - on their own time. Over eight in 10 of study participants (83 percent) say they are interested in learning about F & I products before entering the dealership.
Doing research before visiting the dealer is very good advice and doing it on your credit union site is excellent advice. When the study found that "46 percent of respondents who claimed to be familiar with the Vehicle Service Contract did not select the correct definition" it shows that more work is needed by the consumer. All dealers don't offer the same menu of products available after the purchase but all dealers do offer a service contract.
Visit your credit union, and the loan officer can assist you in knowing the price of the vehicle whether it is new or used. If you have a trade-in they can give you an approximate value. They can tell you what your monthly payment will be and for how long - but remember this is based on the final price quoted by the dealer.
Here's other Tips for Buying a Car.