Synthetic clay blocks have gained popularity for car detailing due to their durability and ease of use compared to traditional clay bars. Here are a few popular synthetic clay blocks used in car detailing:

1. Nanoskin Autoscrub: Nanoskin offers a range of synthetic clay products, including their Autoscrub series. These blocks are made from a rubber-like material and are known for their effectiveness in removing contaminants without marring the paint surface. They come in various grades (fine, medium, aggressive) to suit different levels of contamination.

2. Clay Eraser: Another brand known for synthetic clay blocks is Clay Eraser. These blocks are designed to be gentle on paint yet effective in removing contaminants like tar, tree sap, and industrial fallout. They are reusable and can be cleaned easily after use.

3. Marflo Clay Block: Marflo Clay Block is a synthetic clay material that comes in a pad form for easier handling. It combines the effectiveness of clay with the convenience of a pad, making it suitable for both beginners and experienced detailers.

4. Brilliatech's Clay Block: Brilliatech's Clay Block offers a synthetic clay kit that includes a clay pad and a quick detailer spray. This kit is designed to safely remove bonded contaminants and enhance the smoothness of the paint surface.

When choosing a synthetic clay block for car detailing, consider factors such as the level of contamination on your vehicle's paint, the desired level of aggressiveness (fine, medium, aggressive), and the brand's reputation for quality and performance. Always follow manufacturer instructions for proper use and maintenance to ensure the longevity and effectiveness of the clay block.