you can connect either an i pod or changer not both i'm afraid
if you have the single slot CD player then you can connect an ipod lead to that as there is an output for a cD changer (its how i connected my Phatnoise system when i had it) therefore you get the best of everything, your headunit, ability to play Cd's and use the iPod
if you have just a headunit and cd changer then no you cannot use the iPod without losing the ability to use the cd changer