Was that damage to the coaxial cable done by the car stereo shop? If so, they should fix this for you by using a proper type of splice, not a twist it and tape it splice. If they can’t do it right, then they should go out of business, that is unacceptable workmanship.
A coaxial line is an unbalanced line, meaning that if the shield has any holes in it, it becomes an antenna for any static in your area. That static filter won’t help, don’t waste your money.