I had a MB ML fr new with air suspension. On one occasion when I adjusted the suspension height it kept going right up to the max and wouldn't go back down. It bounced along in aanner you describe and was undrivabke unroll sorted. Really loved the ML for looks, comfort etc. Howver was troublesome really for a car Owned fro new. Passenger side front wheel bearing had to be replaced after two weeks. Turbo initially repaired under warranty., back twice with oil leaks on it then replaced. Either a problem with the quality of the components or the work of the mechanivs. Series of other minor issues had to be sorted as well. Dealing with MB service was OK but very expensive. Just changed it at 110000 miles for an RX450h and so far Im pretty pleased with it. When checking out before buying had nothing but very good reports about Lexus reliability and service.