How to load one external swf over another

Hi, i just made my first full flash site. A really basic one where i load external swf’s on a single layer at different points. Each swf is loaded into a container as this was the only way i could position them.

The only thing is, because i loaded all my external swf’s on one layer, i cant show them loading over another, it just jumps from one swf to another instead of a transition like i intended.

I figured i could do this if i loaded the swf’s on level 1, but this way i cant position the swf’s (or can i?)

is there a way i can load exernal swf’s so they transition over the other?

such as this site www.vetturainc.co.uk.

any advice would be awesome, thanks.