Complex sentence: Curb feelers are still used on some hotrods where a 1950's look is required and are especially popular for cars with whitewall tires which can lose their white coating when scraped against the curb.
Split into simpler sentences: Curb feelers are still used on some hotrods when a 1950s look is wanted. They are especially popular for cars with whitewall tires which easily lose their white coating when scraped against the curb.