How to make the slote of the car body

[jerrylong]

Hi I am using XSI 4 to model the Lambogini, by poly and subdvide.Could anyone give me some detailed steps of how to make such slote of the car body
http://bbs.chinavfx.net/attachments/200411/14000758-1.jpg
Now my model is like this
http://bbs.chinavfx.net/attachments/200411/14000914-2.jpg

[3Dan]

In Max i chamfer these lines and extrude inwards the resulting faces three times at a very very small distance.
Hope it helps.