Yes you have. The 00R and 03 Cobra have this part stock it is called the cross member #4 differential pinion brace.
This is what it looks like.
There is no reason to change it, but you can buy higher durometer urethane bushings from Steeda or Kenny Brown that will decrease differential movement and help control hop.
I ran this by my local shop and they explained that we already have a similar brace on our car. Also, I don't know how you feel about kenne brown bracing, but my experience in looking at their strut tower brace(front and rear) is that there would a very small difference in stiffness with their products, except for their subframe system which seems to work well.