AutoCart Plus will add a new attribute to product page (under "General tab") to select if product must be automatically added to customers shopping cart.
You can add as many products you need and auto-added products can not be removed from cart and quantity is always set to 1.
AutoCart Plus is a very useful extension in case you need to add mandatory products to any order in your store (for example: PDF or paper catalog, mandatory bundle, etc...)

AutoCart Plus is fully multi-store compatible and all settings are managed via Magento backend.

IMPORTANT: Supports only simple products.