What size storage unit do you need for a car? You'll be surprised how little space it actually takes to keep a car safe. A 10x20 storage unit is the standard size for most cars. That's 200 square feet—about the size of most one-car garages. It fits sedans, SUVs, and most pickup trucks. Here's your car storage size guide: Compact cars (like Ford Fiesta): 10x15 unit saves you money Most cars (sedans, SUVs, pickup trucks): 10x20 standard size Larger vehicles (Ford F-150, commercial vans): 10x25 or