Well, shallow depth of field, is mostly what I see. I'd just take any old (preferably old, yes) lens and shoot it wide open.
How do you define 'tones'?
I have a feeling this is one of those choices that's informed by parameters that will forever continue to evade operationalization and remain in the fuzzy realm of vague terms that have no clearly defined meaning.
PS: I LIKE the car shots in the first post. Let that be said. They're pleasant.