Carrier/rack problems of the 2006 Mazda Miata

2nd request, no response received from 1st request I bought my 2006 Mazda Miata from carmax (sanford, FL) in 2011. My car began flooding every time it rained. I have had at least 50 floods to date. The interior of the car has extensive mold damage and mildew. The floors are rusted. The bolts that hold the seats in place are severely rusted. One seat no longer can be moved on its' track. The driver's seat slides out of place while driving. The seatbelt on the driver's side no longer retracts. Roaches are living in the car. I contacted carmax but they were unwilling to take the car back. The car was in the showroom and not on the lot. I'm guessing they knew of the problem. The 2006 and 2007 Miatas have faulty/defective drains. Mazda is aware of the problem but never did a recall. They also expect $1000. 00 from me to fix the problem. I continue to have flooding every time it rains, so it's three years of flooding at this point in time. The vehicle needs to be considered "salvage" at this point due to the years of extensive water damage.