I just got back from a Special Finance conference. After going to several different seminars, I found out that Buy-Here-Pay-Here (BHPH) dealerships seem to be doing better than most other dealers right now. The reasons are that with a bad economy, more people have bad credit and do not qualify for normal financing, and that more and more companies are using Starter-Interrupt devices with GPS.
Customers that are required to have a starter-interrupt device on the vehicle have a 5% +/- delinquency rate, while even people with decent credit have been recently showing delinquency rates of 20-35%.
How does it work?
Starter-Interrupt devices require that the customer make timely payments, otherwise the vehicle’s started is disabled and the vehicle will no longer start. The GPS portion of the device tells the tow truck company exactly where the car is.
With results that good, how long will it be before good credit lenders start requiring starter-interrupt devices on car loans?
Good and perfect credit banks will probably never require the devices. It would make the buyers choose other lenders. However, I believe lenders may start giving the customer a discount on the interest rate should they decide to have the starter-interrupt/payment reminder system installed. It might not be a bad thing given the number of repossessions that lenders are seeing right now.
If you are having a tough time getting approved for an auto loan, there is probably a company in your area installing the starter-interrupt devices on their vehicles and those devices can make it easier to get approved for an auto loan. For some, it may be their only option.

how do i unhook the device that stops my car from starting
Darrell,
Did you pay off the loan? If you did, you should not need to enter the code anymore.
If you did not, you do not want to violate your contract. It is a big deal.