I bought a used car on the condition that certain faulty equipment would be repaired under a "we owe" agreement. I have been unable to take possession of the car after buying it a week ago due to the fact that the faulty equipment technically makes it illegal to drive in my state in the U.S. The seller supposedly already repaired the equipment once but it was not working by the time I went to pick up the car, so I again left it there and they are repairing it again.
My understanding is that the normal 3-day "cooling off" period for consumer purchases does not apply to cars sold by a seller with a permanent physical sales location, so I know that would not have helped me even within the first 3 days after the purchase.
The "we owe" agreement expires 30 days after the purchase date so I would think anything close to 30 days is excessive for a seemingly minor repair, especially if they have had the car in their possession the entire time.
If I think this is dragging on too long with a seemingly simple repair, are there any terms under which I may be able to cancel the purchase even if I signed the "as-is car sale" agreement, and if so, what would be the shortest "reasonable" amount of time to allow them to deliver on their promises?