Shot peening is a process where they shoot metal bearings at the parts being treated so that any small surface cracks are removed. This will increase the fatique resistance of the parts meaning they can withstand more revs before starting new surface cracks. Surface cracks can eventually grow and lead to failure.
Meaning: yes n/a cars will benefit from shot peening. It will lenghten the life of the crank.
Sorry for being so technical. I can clarify if need be!