All of the companies, and possibly even different agents, will have different policies and responses. But always keep records of what you had, pictures and/or receipts. It never will hurt and only help. I was told I needed to increase my insured amount when I mentioned the aftermarket parts increased the value of the car a lot (not a small fraction of the cars worth).
But there is no blanket answer because costs and values are different. Let’s say you have a car worth $40K and have it insured for $40K. If you have a stereo worth a grand and it gets stolen. That $1K in losses is 2.5% of the cars worth. Here you are asking for a small amount back for what you are paying for. And if the car was stolen or totaled and you said “Oh and I had a $1k stereo in there too†they would probably say “no problem†because who knows if you had actually a $40K or a $39K car (dents can deprecate a car that much) and they want to keep you as a customer.
But let’s say you had a car worth $10K and insured it for $10K. If you had a $5K system and it got stolen. Even if you had proof of having it there is a good chance they will say “no wayâ€, that is 50% in losses. You were paying to insure $10K worth of property and you actually had $15K.
And don’t forget about you deductible, if your system is worth $1000 and you have a $500 deductible, you will get $500 from them. Basically ask you agent.
Just my $0.02