I fought a ticket like this (and many others) when I was living in Tahoe. I searched and searched and as of 2000 this was all legit info. If new laws have been put in place, some or all of this might not be accurate.
Any light mounted above 42" inches is considered an "off-road" light. Any light mounted under 42" is considered an "auxiliary" or "driving" light. What you need to do is look up vehicle code 24402. As long as you can show evidence that your lights are indeed "auxiliary" and not "off-road" the lights do NOT need to be covered. Keep in mind that you can only have TWO auxiliary lights. If you have more than that uncovered you might be out of luck. There also isn't anything that says you have to cover an "auxiliary" light that is over a specific wattage. Only your primary lights must remain at or below legal limit. You could have two uncovered 10,000 watt 20" lights on the front of your truck and nothing would be illegal about it... assuming it could not be illuminated with the high beams on. That's key too, your "auxiliary" lights can only be used in conjunction with your low beams. If you run your highs and your "auxiliary" lights at the same time it's illegal. The DOT doesn't have any specifications or regulations as to recommended wattage for auxiliary driving lamps, so take that AMMO to court and get the ticket thrown out. Also, when I fought my ticket, the CHP had nothing in their books that stated they have a regulation regarding light requirements in their books. CHP can make up whatever they want but it's only legit if it's been approved and is somewhere in writing before you are cited for it.
It's a total BS ticket if in fact you're lights are mounted below 42" inches. If they are at 42 inches and you don't mind bending the rules, let the air out of your tires or borrow some smaller ones. If the cop did NOT measure your lamps at the time you were cited BE SURE TO TELL THE JUDGE THAT! It's obvious the cop does NOT know the law if he's out writing this ticket to people with lights mounted at or below 42" inches. Any Judge worth a damn will have enough sense to dismiss this case. If you are legit, and lose, appeal it. Some of the smaller courts have Judges that just have no vehicle code sense whatsoever.
I've fought 17 of my own tickets and have only lost 3. Do your homework, let the law be your guide, and don't let those bastards win. Somewhere I have my tickets and related court paperwork, just not sure where. If you take a decision passed by another court located in California you have a 99% chance that the court you are in will make the same decision based on prior judgements. If you can find someone that fought this ticket and have the ruling number, TAKE THAT INFO TO COURT! If you can get a Judge to drop a ticket for going 135mph on the 241 you can do almost anything.
Aloha