Opel's rhymes with:
opal's, apple's, apples, capel's, caples, chapel's, couple's, couples, cripples, cupples, dimples, disciples, examples, gospels, grapples, koppel's, krapels, maniples, maples, metacarpals, multiples, municipals, naples, napoles, nipples, opal's, participles, peeples, people's, peoples, peoples', pimples, pineapples, principal's, principals, principles, pupils, purples, ripples, sample's, samples, scalpels, scruples, sharples, snapple's, snapples, staples, steeples, stempel's, subprincipals, teeples, temple's, temples, topples, tramples, triples, waples, whipple's
Opel's sounds like:
oblak, oblige, obliges, oblique, opal's, opalka, ophuls, ovules