Soft coasters can provide a cushion that absorbs some of the impact of bumps in the road, so they can be the best car coasters for helping to prevent spills. However, no coaster is likely to absorb enough of the movement to completely avoid spills from happening. And condensation is another key concern. It also helps keep out the crumbs and other dust and grime fro reaching the bottom of the cup holder and will attach to and absorb those as well to keep your car cleaner with a cute stylish touch!