Discount buying two products

Anyone any information as to implement a special offer on two products that are on a regular price each, but when bought together a discount kicks in? Also need the two products stockroom quote to be deducted upon purchasing the special offer as well as customers buying the products separately. If the only way to do this is through coupons, is there a way to pass a coupon code through to the payment cart without the customer entering it manually?

thanks

Coupons would approach that and you can easily load them automatically in the cart with the "auto load" option of the coupons. However, you won't really be able to restrict a coupon so that it only applies when two specific products are bought together. You can only tell the system to use the coupon if two products of the same category are bought together, so it could even be the same product with a quantity of 2.

Doing that what you want would require a custom plugin to be built