i would add lubricating windows to the list for sure... i do mine once every 2 months or so.. probably dont need to do it that often.. but its easy and cheap so why not... other things i would add to the schedule (if they arent there already).. conditioning leather seats.. some type of protectant on the top of the dash and door panels to prevent fading and cracking (both should be done more often during summer months of course) and i and many others here change their PCV valve every other oil change just to be sure its not failing, dont know what the manual says for that, but it cant really hurt to change it more often than the manual calls for