No, it's not too late to undercoat your car. Undercoating can be applied to vehicles of any age or condition. Newer cars can benefit from undercoating as a preventative measure against rust and other corrosion, while older cars can benefit from it as a way to slow down or prevent further rust damage.
In general, the best time to apply an undercoating is before your vehicle shows any signs of rust. However, even if your vehicle already has rust, undercoating can still be effective in preventing the spread of damage and protecting your car's metal components.
