Exhausts is a whole debate of my it's own! Formula Dynamics and many others recommend Larini, which I have, and the noise is truly sublime. Really, I have yet to hear a better noise, Ferrari and Lambo etc included. Trouble is you need the full system to really open the sound and it's a large bundle of cash. Some also find it too loud but I think that this is only the case if you use it as an only car or if you are more into the continent crushing ability rather than the event of each drive. There are some who prefer Quicksilver etc for these reasons which is totally cool and each to their own.
Formula Dynamics offer a host of upgrades and the best places to start are suspension and the drive by wire enhancement module. Actually Mike on here (mjheathcote) has an unused set of their springs for sale for less than half price. The DBW module enhances the shifts and makes more of the CC gearbox whilst also (allegedly) extending clutch life.
After that it's time for brakes. Starting point is better pads (EBC Yellow stuff or similar,lots of choice here), braided hoses and better quality fluids. You can change the callipers and discs to much larger, higher spec too but again this starts to cost serious money.
Finally, more carbon is good! Start with the FD carbon paddles which revolutionise the shifting as the standard paddles are too small for mid turn shifts to be natural. From there, carbon rear spoiler, carbon door inserts and if you really want to get carbonised (!) You can even get headlights in the stuff!!
After all that, a proper suspension set-up and great tyres will give you a GT3 from Italy. More focused, more aggressive and more smiles per mile.
I promise you will add it to your Bora and Tiger on the "never sell" list!
All production cars come with some market driven compromises. You can dial these out and make it your own if you like.