ive been to a house with a garage that had that on one side of the garage.
Two car garage that had the entire floor done in the diamond plate pattern one.
even with oil spills, stuff gets through and lingers in there forever. the garage is now half-and-half.
bare concrete repainted all over, and then half in the diamond type interlocks again. reason being is that the show car is on the interlocks, and the work area is on the concrete, because removing those interlocks to clean a work area when something spills is a bitch because of their interlocking nature.
I say if your garage is in somewhat of a shamble, or neither clean nor dirty in great variance, i'd just try and use a concrete filler, get it as smooth as possible, and then use a hand floor-sander (it looks like a swiffer sweeper but its heavy duty and has sandpaper attachments at the bottom).
smoothen it out during application as much as possible. sand it with the tool, and then use concrete etching primer (also amazing for removing and preventing rust, as it containts 50+ % of phosphoric acid, which is the highest concentration i could find).
once the concrete is a nice dull, but bright grey, i would paint it with Rust Bullet.
Rust bullet is being used by the US Navy to coat the surfaces on which their fighter jets screech to a grinding halt at 200mph landing speed upon their aircraft carriers, just as a reminder.
should cost you roughly 120 bucks to do the entire job.