That's a great idea! But I'm not sure you would use a potential subjunctive in this type of conditional -- at least, not in the protasis. The point of a "You might be a redneck" joke is "If you have ten broken chariots (now, in the present), then it is possible that you are (now) a redneck." I think Latin is most likely to use a present indicative in the protasis, and forsitan + subjunctive or fortasse + indicative in the apodosis. E.g.
Si decem fractas aurigas in trocleis in tua area habes, forsitan sis rusticus.
Note also that the predicate nominative, rather than the accusative, is used after forms of sum. Your initial version was missing a form of sum in the apodosis; i.e. it should have been possis esse rusticus -- but as I said, I don't think that's the best construction in Latin anyway.
Incidentally, I think rusticus is generally a good translation for "redneck," with both its positive and (sometimes) negative connotations. See, for instance, Propertius 2.5.21-26 (speaking to his unfaithful lover):
nec tibi periuro scindam de corpore vestis
nec mea praeclusas fregerit ira fores,
nec tibi conexos iratus carpere crinis,
nec duris ausim laedere pollicibus:
rusticus haec aliquis tam turpia proelia quaerat,
cuius non hederae circuiere caput.
I would not tear the clothes off your faithless body,
my wrath would not break down your door,
I would not dare to pull your braided hair
or hit you with my angry fists:
a redneck would seek out such shameful fights,
whose head is not wreathed with a poet's ivy.
Dic mihi, Damoeta, 'cuium pecus' anne Latinum?