why is it crazy? the depreciation on a 4runner is low enough that short of some huge economic change that depresses the cost of SUVs you won't ever be underwater and auto loan rates are lower than the return you could get from that money elsewhere.

it looks like penfed rates have gone up a bit from when I got my loan, but let's use todays interest rate of 3.74% and assume a loan amount of $35k. after 1 year the balance is $28.5k, is a 1 year old 4Runner worth at least $28.5K? Yes. After 2 years the balance is $21.8K, is a 2 year old 4Runner worth at least $21.8K? Also yes. After 3 years the balance is $14.8K, is a 3 year old 4Runner worth at least $14.8K? Still yes. But if you're still really concerned about it, gap coverage only costs about $500.

using todays rates (3.74%), the cost of financing a $35K loan is $3,429. Over the same time period that same money in a high-yield savings account would earn you about $3,325 or if you parked it in CD savings you could expect a return >$5k, and if you put it in a mutual fund it would probably be higher.

60 month financing might put you upside down on a loan for a used vehicle, or for vehicles with a lot of depreciation, but on something like a new 4runner you might as well take advantage of the low auto loan rates.