Car insurance add-ons are extra coverages you can buy to enhance your basic policy. They protect against specific situations like depreciation (Zero Dep), total loss (Return to Invoice), engine damage, breakdowns, and losing your No Claim Bonus. Other add-ons offer roadside assistance, key replacement, and cover for passengers or personal belongings. They cost extra but provide better financial security and peace of mind by covering what standard policies don't. Choose add-ons based on your needs and car's age. 

Health insurance add-ons, also known as riders, are extra benefits you can include in your base health insurance policy by paying an additional premium. They offer enhanced coverage for specific medical needs or situations that the standard policy might not fully cover. Think of them as customization options for your health insurance.