This is common knowledge and I'm certain it's posted at least a dozen times on the forum. The 318ti shares the same front end as the e36 sedan from the "A" pillars forward. This includes, but is not limited to, the fenders and hood. There was a change in sidemarkers in 09/96 and the fenders are different. You'll need the newer style if you want to use your old sidemarkers.
I highly recommend that you familiarize yourself with
www.realoem.com . You can plug in the last 7 digits of your vin which will allow you to find EVERY single part number for your vehicle. From there, you can do a part number cross reference by clicking the "search part number" button at the top of the page. Then all you have to do is click the "search vehicle by part #" link, paste the part number in the box and you'll see exactly which vehicles use compatable parts. For example:
http://www.realoem.com/bmw/partxref....ur=&series=E36