by box I assume they mean a cargo box attached to the roof rack.
I drive a 97 Outback Sport. A boxer 4 is in no way a v4. V in engine terms refers to the layout, such as 'boxer'. V means that the piston run in a diagonal fashion. The term 'boxer' comes from how an exploded diagram of the engine looks. Pistons laying flat pushing out. Subaru is known for this. They use it because of the above stated points, balance, reliability, etc. They aren't the only company to use it though, Porche, Ferarri, and other high end cars use, or have used horizontally opposed engines. Balance and center of gravity being the main reasons for use. Think about where the crank shaft is on a V engine. It's at the base, same goes with the boxer, but the rest is at that same level, giving it the low center of gravity, and with how much an engine weighs, that translates to great handling characteristics.
Subarus are defenitly safe. The forester sets the standard in it's class, none perform better. The legacy line does well also. The impreza is on the same chasis as the forester, so it's very safe too.
Get one, any year, any model, as long it's had is scheduled maintenance, it will run forever.