Don’t be afraid of your slide. They are not the delicate little things that some people imagine they are. If you ever spend any substantial amount of time at a dealership you’ll see them moving trailers around on tractors and forklifts with the slides in various stages of extension. They’re not going to fall apart if your a centimeter out of level. Do make sure you don’t close them with trash on the roof. Toppers are a huge help with this. After nine years and probably 70,000 towing miles I have yet to sweep the roof or treat the seals. Come Thursday I’m putting another 20,000 or so miles on it and the slides seal nicely. My owners guide for my Outback recommends no lube on the rack and pinion so I have diligently followed that recommendation and so far no problems. Enjoy the extra space, it’s so worth it.