If you have a graphite rear upper deck or the Penguin rear upper deck. I have found a super easy way to mount the HPI Titanium Antenna onto these decks.
Bassicly you take a stock rear upper deck and pair of good zizzers (spl? LOL). Cut out the antenna holder as you see in the pics. Then use a dremel to sand off the areas around the antenna holder, it makes it look nice. Then you have your Titanium Antenna Mount. Also using a stock rear diff bolt and a rear upper deck stock screw to hold it in place.
Here is where you cut on the stock deck. You can also use double sided tape to secure the antenna mount and can also work with other antenna's as well, besides the HPI Titanium one.