Ouch! Looks it's about a 50 minute ride on Saturday morning to the Fontana station, then wait for the train, then 1 hour 25 min on Metrolink and then however long it takes to go to Santa Monica frm there.
I also checked the SuperShuttle website, and apparently they don't even offer service from ONT to Santa Monica. On this route, they only have ExecuCar at $98
.
Are there any ONT - LAX express buses? I know LAX is relatively close to Santa Monica.