I'm new to the BV5 commerce product, so please bear with me. I see that there is no differentiation between the cart and an order. A simple bit field in the Order table indicates whether an order has been placed and effectively becomes an "Order" rather than a "cart". I also have noticed that the "cart" is persisted between logins via cookies (which I know can be turned off). Currently, we are using the BV5 Commerce package as an engine and are exclusively using web services for communication. Here are my questions:

How do we retrieve the active "cart" for a specific user without retrieving any "orders" (the web method Orders_Order_FindByUser will return all orders)?
Where in the code is the "cart" associated with the user the first time?
Will there ever be more that one "cart" associated with the same user (could we simply filter the order list based on user and isPlaced?)?

I know we can modify the code to do what we want, but I don't want to re-invent the wheel if I don't have to.

If this belongs in the customization section rather than here, could a mod please move it to correct location?

Thanks in advance for the help.