This usually comes up whenever the Custom Search Tool gets a little traction and a new audience is taking it for a test drive. I would post this on the facebook group where all this is getting posted, but I'm still waiting for approval to post in the group.
The Custom Search Tool will search for the exact options you tell it to search for. It's on you to search for an option combination that actually exists, the site isn't going to sanity check your search for you. So if you search for what you think are the options your car has but get 0 results, it isn't because the site is inaccurate. Its because you searched for a combination that doesn't exist.
Pretty much everyone gets tripped up with the interior colors. They just choose the color of their interior and run with it. They don't go to the trouble of making sure they are picking the right RPO code. Everyone who I have helped who ran into this had selected the wrong interior. For example... HTT and HTP. Both are jet black with sueded seats. But one is only available on 2LT/LZ cars, while the other is only available for 3LT/LZ. If you have a 3LT and pick the one that can only come with a 2LT... you will get 0 results. This tool returns accurate results, but you have to do your part. I've tested it on dozens of random cars. It works.
The Custom Search Tool is by far the most resource intensive part of the site. The table that holds the options data for all the cars currently has about 13 million records (roughly 120 RPO codes for each car, over 100,000 cars in the database). While this isn't a big database by any real standard, its quite taxing on the small instance it runs on because I'm not trying to pay a pile of money out of my own pocket to run this free site every month (the ad revenue usually just barely covers the bills). Generally, peak traffic to the entire site might be about 50 concurrent users. Only a few will be using the Custom Search Tool at any given time on a normal day. The site has been handling that trouble free for the last several months. Today, there were 100+ concurrent users trying to use the Custom Search Tool for over an hour, along with the normal user traffic to the other parts of the site. The database just couldn't take that beating so I had to disable the tool. It's possible that I will have to disable it again tomorrow. Sorry for any inconvenience, it just is what it is.