Downtown's rhymes with:
downtowns, downtowns, downtowns, downtowns, town's, townes, towns, brown's, browns, browns', clowns, crown's, crowns, down's, downes, downs, downtowns, drowns, frowns, gowns, kouns, nouns, town's, townes, towns
Downtown's sounds like:
daunting, demanding, demotions, denomination's, denominations, denoting, denting, denuding, detentions, detonating, detonations, dominating, donating, donations, downtowns