I agree a real tracking system is a must. I vote for the cheapest & easiest one you can buy. We built ours at the time and I consider that to be a mistake, would have been better off just conforming to someone elses implementation. But either way, have to have it.

You're right that if you're not a higher level manager you can't directly implement, only try to influence - which you seem to be doing! One thing I've thought about and discussed in other posts - but not actually tried yet - is that I think a departmental or team blog might be another way to open up the process. Imagine you have three DBA's that maintain one central DBA blog. Any time there is a reboot scheduled, any type of issue, patches added, post some not too technical notes about why/how long/etc. When you send out the company wide email "server will be down for maint" instead of putting the explanation in the email, point to the blog. Not a lot of people will read it, but a few will, and if you stick to the same idea of being totally honest and open, sooner or later that builds cred with those that matter. It's also one of those nice things your boss can point out to other managers as far as transparency, using the "latest" technology aka blogs, etc!