You may want to consider the 72-month option if there are special promotions happening. Sometimes, Toyota Financial will offer 0% or 0.9% financing for qualified buyers. If you have a top-notch credit score and good income, the 72-month loan might be the better option anyway.
If you still want an 84-month loan to fit your budget, shop around. Banks, credit unions, and online lenders are more willing to offer 84-month loans than ever before. You will end up paying more interest over the life of the loan, but you get the benefit of low monthly payments in the short run.