Sounds like you're talking about the state of California crvp...My dealer did my paper work so it was sent out the day I took delivery, took about 7 weeks...Have seen 6-8 weeks reported so 30 business days sounds about right...
The rules currently state you have to keep the car for 30 months and if you no longer own the car (car could be totaled due to no fault of your own) you pay back the prorated rate...$1500/ 30 months is $50/mo, so in your scenario of selling at 24 months, you'd need to pay back $300...If I think you'll find the resale value very unappealing, though...
Lastly it's reported on other forums that people are selling there cars and not getting crvp bills...No one seems to know why some are reporting crvp bills why others are not...