JoPedition,
Since you mention that you have been searching Walmart and Amazon for storage gear, my own experience might be helpful. EP is a great resource, but the shopping advise tends to be on the expensive side...
For car travel, my latest go-to is a $5 school backpack from Target (got it on clearance in October). It opens at the top, has two padded sleeves inside for tablets and laptops, and with an extra t-shirt and socks I usually carry is plenty of padding to store my DLSR and a lens or two. I have a "photographer's" backpack that has all the movable storage compartments where I can store extra lenses, flashes, light modifiers, batteries and cables, chargers etc. I have been considering a pelican-style case from the local Harbor Freight store for $40 or so just because the straps and the shape of the bag means it gets hidden in the vehicle easily or tangled up with other gear.
The cheap school backpack is pretty low key also. I don't feel like I'm advertising $2000 worth of electronics in something easily snatched. It didn't stand out on our family trip to NYC, it's subtle at weddings were guests are on the look out to avoid the photographer, and it's easy to grab from one of the seats when I'm on the side of the road photographing wildlife.