The NSX power windows are notorious for being slow in moving up and down. Prime user Hugabuga created a “window regulator upgrade” kit which initially involved the modification of the regulator mechanism to replace a cable guide with a pulley. The kit was subsequently modified to add some customer teflon sliders. This has proved to be a very popular and effective solution to the problem. The evolution of the kit can be found here. The vendor page can be found at here. While installing the Hugabuga mod, a number of people have reported finding that the slider mechanizm was slightly deformed which causes it to bind in the track. Here is one thread discussing the problem and potential remedies.