Underbody Shield problems of the 2008 Jeep Liberty

Bought the Jeep new from Jeep dealer and it came with a factory installed 'skyslider'. We hardly ever use the skyslider and after a severe thunderstorm, we noticed when driving the Jeep, there was a popping noise. The skyslider had bunched up and was not closing. Took the Jeep to our mechanic who advised that there was a 1" piece on the track that was broken and the part would cost approx. $1900. !!!. I called Chrysler because the Jeep is only 4 years old and this is a clear defect. Chrysler advise me to take the Jeep to a Jeep dealership for diagnosis. . . A broken piece on the frame which needed to have the whole frame replaced at a cost of - $4k. Four thousand dollars. The skyslider is defective on all 2008 Jeep Liberty models and this could cause a fatality. The skyslider is made of canvas and can pop off the track and fly off. I cross a bride daily and cannot drive more than 20mph or the roof starts to lift up.