While I personally think that the de minimis argument should probably have broader bearing than it currently does, you can somewhat skirt the issue by applying a level of parody to the object or reference you actually mean to invoke. GTA has always done this by creating parodies or proxies of real-life cars -- they have attributes and styling cues that are similar to the real-deal, but aren't, and don't use any trademark from the authentic one either.

This approach is a little harder to apply to easter-eggs, because the knee-jerk reaction is that they feel less easter-eggy if its not the real thing, but I think that doesn't actually have to be true. For example, if you wanted a Mickey Mouse cameo, you could probably come up with parody of him, or a stand-in that invokes the authentic article through styling rather than likeness, and those would likely be safe, and yet everyone would still get that it's kinda-sorta meant to be Mickey Mouse -- you can lose the threat(*) of a lawsuit without losing the joke.

(*) As always, I am not a lawyer, nor are most on these boards, and even if some are, their advice here on this forum is not legal advice. Your best course of action is always to consult a lawyer who understands not just IP issues but IP litigation -- you can be threatened or sued even if your use is non-infringing, and you won't likely recoup your defense costs even if found innocent. One of the many services a lawyer will provide you is advising you of your risk relative to your intended actions -- they're not just there to assure you that you'll win in the case that you are sued, and its always cheaper to avoid litigation entirely.