flat charge/flat rate

my client (for who i design a website incl a hika shop) wanna have for every product-order a additional "flat charge", with other words: i go in the shop, order 5 pieces candy, each 5 euro, what makes in total 25 euro plus a flat charge of 20 euro plus tax and plus shipping costs. anyway...i could not found any option to do that...the "flat charge" will be permanent and for every product! so what can i do to get that listed and calculated?

There is no option to do that.

That will require some view customization in order to parse the cart during the checkout and add/update that "charge" product dynamically in the cart.