Chevrolet, as a word, is very pretty, imo. I don't think I would use Chevy as a nickname - my first thought for a nickname was actually
Layla, more as a "normal" fallback than a nickname.
But, there's not much difference from Chevrolet to
Mercedes (as already mentioned). Or
Bentley,
Royce,
Aston,
Porsche, etc. I knew a guy named
Ram, after the Dodge. So ... Different strokes.
Having said that, I hope this isn't a conception name like
Brooklyn or
Paris ... What's next? Kitchen Table? ;)