Over time, however, rubber seals can wear out due to exposure to UV rays, extreme temperatures, and regular wear and tear. Signs of deterioration include cracking, stiffness, or noticeable gaps that allow elements to seep into the vehicle. If you notice any of these signs, it's advisable to replace the seals promptly. Ignoring worn-out rubber seals can lead to various problems, including water leaks that could damage the interior or electronic components of the vehicle. Additionally, reduced sound insulation can make for a noisy and uncomfortable ride.