That one is quite high price! Or have these started to go up? Mine was 13k with only 2900 more miles in 2014, and that was deemed expensive by some
Anyhow, one quick and easy mod I can highly recommend for the convertible is one touch power windows up. It involved chiselling away the notch on the window switches that stop the rear windows from auto winding up when you pull up the switch. You just then have to code in the power windows up in the smartphone app and you're set.
Keep an eye out for one of the southern meet threads, if we go to the same one I'm happy to do whatever coding you need