It is not altogether easy to get insurance for modified vehicles. However, there are some insurance companies that specialise in these types of cars, as well as modified car insurance. In many cases, insurance companies view the owner of a modified car as a racer, instead of someone who is an enthusiast.
Car enthusiasts often modify their car and it takes a great deal of effort, money, and time to get your car looking to your specifications. In general, modified car owners are ones who want their cars to be different from the standard cars driving down the road.
Now most insurance companies specialising in modified car insurance will have some requirements, but they may not be as bad as you think. For example, it may only require that you be of a specific age, such as 19.