This is what I do these days too. Just move things in, and the space behind thanks to the curves is just an extra cubby. My top cabinets are supported by my bottom ones, and just secured it at the top to prevent tipping. The ends are a straight cut on the wall side, but the bottom shelf extends to the wall. In that cubby I keep my garbage bags, paper plates, & more.
With the bottom cabinet behind the driver, the space between it and the wall stores my walking sticks, a machete, and an aluminum baseball bat, all easily accessible from the drivers seat. The gap at the other end holds my hand broom, dustpan, & cleaning supplies.
In the end, it’s not wasted space at all, and really quite handy & convenient.
"I start saving money with the vehicle purchase,
and pay practically nothing to convert it." ~ Road Warrior