Neglecting to declare car modifications can invalidate your insurance policy, leading to rejected claims when you need financial protection. If you don’t declare modifications and need to make a claim, the insurer may refuse to pay out or provide a reduced rate. This could leave you facing significant out-of-pocket expenses for repairs or replacements. Moreover, modifications that break the law, such as illegal wheel changes or excessively tinted windows, will void your insurance if not declared. Not declaring modifications can result in your insurance being invalidated and your claim being refused when financial protection is needed. The consequences of not declaring modifications can be severe, so it’s always best to be transparent with your insurer.