I've had quite a few built cars, I've never told my insurance what was done to them. However I didn't want to pay high insurance for a car that's build like a brick s**** house. I'd only say it depends with where you live, How much you really want it covered. And how often you're going to drive it, Those are the three things you should look at when considering if you want to insure a race car.

If you're stupid enough to put modifications on your vehicle without declaring it, you shouldn't be driving.

I do, if I get in a crash then they are covered. I don't want to spend $2k on a lift, have a drunk driver hit me, then be out a lift lol.

LSX wrote Do you declare mods to your insurance? I want to put mods on my car but if I tell them they'll obviously raise the cost, but I heard if you dont declare it and you have a crash.. your insurance wont cover you as you didnt declare the mods?

I'm gonna take a guess and guess you're living in the uk.
Just ring your insurance and ask "if I was to add .... to my car would my insurance go up or do I pay a one time payment"

Some insurers, if you persuade them enough it's not a performance enhancing mod ( even though it is) they'll charge you like £40 and that's it.

Red any more help PM me

If you are rich enough you should probably get insurance, although me myself wouldn't tell my insurance company about any mods... If you're going for MOT or whatever you will need to change the parts back to stock.

All you have to think about is, can you afford to write off your car without getting any money back after.

Yes, you should always declare your mods..

I do, only because if I wanted to sell my car- to an enthusiast, or someone that knows what it is... Then it is worth almost an extra third of what it would be without the modifications.