I've considered this pump as well, but if you look at the reviews on Costco's website the limited battery capacity can be an issue. If you're expecting it to inflate a large flat tire from zero to 32psi, it may or may not make it. Much better than nothing, of course.
It is good for convenient adjustments; a friend of mine runs motorcycle tours and carries a combo jump starter/tire pump. It's also great for garage use in making adjustments for cars, bicycles, motorcycles, etc.
Power does not "pass through" to the pump motor if you plug it in to the car, and can take several hours to recharge.
All in all, I'd go with a good 12V inflator that can sit in the car for years but still work fine when needed. It is important to test it to make sure it's not going to pop the cigarette lighter fuse, and so that your wife knows how to use it. (And is she willing and able to plug a tire?) There are faster 12V pumps that attach directly to the battery, although that's obviously not nearly as convenient.
There's an inflator and a Nealey plug kit in my wife's car, and even though she's not the least bit interested in learning how to use them, I've coached one of her younger co-workers over the phone through plugging and re-inflating a tire. It never hurts to have the means to handle simple punctures on hand, and it's often helpful.
