If you want to go to the trouble, you will find most HOA's do not fully abide by their bylaws. Things like required number of meetings per year, # of members present to vote or hold a meeting, timely recording and posting of meeting minutes, notices to homeowners.
A good lawyer with HOA experience can often get HOA declared invalid because it is not following it's bylaws. Once they know he is snooping, he has to act fast, before someone retroactively "fills in the blanks".
There is a good chance you can win the battle by either finding errors with their proceedures, or, as previously stated, questioning the definition of a truck - pickup, Chevy Taho, Suburban, Caddy Escalade, Ford Expedition, older Explorers, Chrysler ram series....
Attack on how they are registered if that supports you, or type of frame and suspension components used.
The problem with winning is that most of the HOA's I have been around are controlled by a few powerful people, who once defeated, will take it personally as a threat to their domination and authority and look for revenge.
For evermore, they will look at you and yours with a fine tooth comb, and fine every reason possible - real and manufactured to put you in the fire. Battle after battle, legal fees....
I know of an instance where the homeowner claims he paid dues, but HOA said never received, and started foreclosure. Now, to protect himself, he has to get receipts from the office for every payment.
This means that if you intend to stay, you may have to protect yourself by running for board or some other position of authority. I don't know about you, but I have better things to do with my life than deciding what colors are acceptable, how high you are allowed to let yur grass grow, and how many pansies you can plant along your sidewalk.