multi-dimensional array help

i have a shopping cart. the shopping cart is really freaking complex. it's using OOP. i currently use 2 MD arrays to store all of the cart products. they are setup like this:

product array:
array_id => product_id => quantity

option/spec array:
array_id => spec_id => product array id

in order to correlate the option/spec array with the product array, i use the "product array id".

let's say a user has productA with optionA + optionB in their cart.
they also have productB with optionC.
they then decide that they don't want productA with the 2 options.

my problem is that of updating the option/spec array's product array id with the new array_id in the product array.

it's so complex right now, i can't think straight anymore.
should i just unset the array and repopulate it? surely there is a more appropriate way...

thanks!

I may be totally wrong here, but it looks to me like you over complicated the situation by working with two MD arrays.

At first glance I wonder why not just store it all in one array, where the item's options were just under another key called 'options'.

I would take steps to make that part simpler and I think everything will fall in-line thereafter.