I'm not a lawyer either, and I haven't even read the above mentioned documents. I won't bother debating the issue of whether it's right or wrong. But, I can tell you what is very likely going to happen if a cop asked you to open your trunk and you refuse. They will not appreciate it. You can kiss your "warning" good bye, you will be detained while they call and wait for a K9 unit to come to the site. During this time you will be handcuffed and made to sit somewhere uncomfortable. You could even slip down at some point or bump your head while be helped into the rear seat of the cruiser.
The K9 will be perceived to "alert" on something and then you WILL open the trunk because they then have probably cause for a search, possibly including but not limited to a full cavity search of your person

. They'll then have a reason to start looking for anything and everything that falls outside the law... laws that you don't even know about. Then they might just let you go with a ticket, after you've wasted a few hours of your time.
Besides, an improper search is only really relevant if an arrest takes place as a result, and you are able to successfully challenge the evidence obtained due to the search being unlawful. This may or may not get the case thrown out, but it won't take the money out of your lawyers pocket and put it back in yours.
While I fully understand the importance of exercising our constitutional rights, sometimes we just have to understand when it's worth it and when it isn't. Long story short, if a cop asked you to open your trunk, you're probably going to open your trunk whether you like it or not. If you refuse, they will assume you have a reason and they aren't going to just let you drive away without finding out why. I may not necessarily agree with this sort of thing, but it is reality. I personally know people that it's happened to.