My dad was an insurance agent at AAA for 20 yrs. I have an "upped symbol" in old AAA vernacular. I am covered for the vehicle book + $15k. (old AAA system lets you increase coverage in $5k increments). I still have the same coverage but Im unsure if this is still available or if I am grandfathered. Some companies do this type of coverage but rules about what can be covered can change yearly within companies.
Other policy options include:
-Stated Value Policy, where you and the company agree on the value each year and the premium is based on that.
-Specialty vehicle policies, Think Hagerty, intended for classic cars and show cars, typically not allowed for daily driving and no coverage for offroad damage last I talked to them.
-Separate coverage for modifications, for when you have a $3k YJ with $20k of parts, take a separate policy out through someone like lloyds who will cover anything. (note that this would just cover the parts, not the cost of any labor, you loose that)
Other insurance items of note. So long as you have full coverage, even if you roll the Jeep on the rubicon/NF trail/private property you are covered under the comprehensive portion of your policy. This is California law.
Having totaled a built Jeep I can tell you that there are some details in the policy you need to note and you will likely have to fight in the event of a claim.
1st: never have a wrecked Jeep towed to a tow yard. Have it towed to your house or a friends and cover it with a tarp. Once it hits the tow yard you will never see it again.
2nd: keep a list of parts used on the vehicle or similar parts that were DIY or if the original manufacturer goes out of business.
3rd: insurance companies have a limited time to settle a claim by law. So long as this isnt your daily driver, delaying settlement on a totaled vehicle can give you better results as they get desperate.
4th: Dont leave a totaled vehicle at a shop unattended. Insurance companies, after seeing quote(s) will call it totaled and send a truck to remove it. Once they have it, it is gone.
When I totaled my silver 05 LJ, then only a few year old vehicle with 50k miles, I was strung around and only saved by my dad's knowledge of the system. First thing I did was tow it home and put a tarp on it. The next thing we did was file a claim. Then we had the Jeep towed to a couple of different shops for quotes. Then we towed it back home and put a tarp on it. The repair claim was denied and it was deemed totaled. Only a few hours later we got a call from the last shop saying a truck from the wrecking yard was there to pick up the Jeep, thankfully we didn't have it there so they couldn't close out the claim. The insurance company called and said they needed to pick up the jeep to close out the claim, my dad told me to ask for a copy of the settlement prior to turning over the Jeep. The first settlement was only book. I said no citing my extra coverage and they said I was only covered for fire or theft so I hung up. 2 weeks later they called back asking why I hadnt signed the settlement. I told them that it wasnt good enough. They later called back with book +5k. I said no and provided a list of parts as well as craigslist adds and ebay auctions for similarly built jeeps selling for well over book. A few days before the legal window to settle the policy they called back with a new number that was middle of the road for the similar jeeps i sent and covered about 90% of the parts in my spreadsheet. I settled for their final number less the buyback cost of the Jeep (buyback cost is the price a wrecking yard was going to pay for the vehicle). With the cash part of the settlement i was able to replace the Jeep with my current one and part out the old one for more than the buyback cost.