Brent have a look at Gary Honis' online model pics for the 450D, even if you don't use hs model it is a good source of photis of the internals of various models, especially the 450D. Just search for 'Gary Honis DSLR modifications' and it will be near the top of the search. I don't think coming in from the SD card side (looking from the rear) is feasible because of the placement and thickness of the rear board and the main sensor board connector to it. The left side is a clear run underneath the usb connector board straight into the back of the sensor - which is why so many people go in that way.
