Employee parking in ONT is easy. For $20 a month, you can park in the day lot 5 for terminal 4 or the employee parking lot (lot D) between the F lot and terminal 2. Both are a 5 to 10 minute walk. You can buy a pass 24 hours a day in an office located in the old terminal building near lot F.
Only $20 a month? That's a steal! The onle problem for me would be the drive and maybe the destinations. I myself am dreading the parking fees at LAX if I have to park there. Then again I live in Long Beach...
We used to layover in ONT - a short drive from home. I just asked the hotel if it would be OK to park in their lot. IT WAS! I parked there and took the hotel shuttle to the airport.
Just a $2.00 van driver tip and a note in the window of my car saying it's OK to park there per so-n-so is all it took. When we changed hotels, I did the same thing there too. It worked great - try it. It'll cost you about $12.00 a month for 3 commutes.