Hi op! Congrats on the new car!
I'd agree with a few of the comments but I'll elaborate!
I'd definitely go with some mudguards: I personally have the rally armors and they were an easy install and super high quality.
Full LED swap: the stock halogen bulbs on the interior and exterior are ugly, a full LED swap probably wouldn't be more than 50 bucks for some stage 2 or 3s from @diodedynamics
Taillights: the only thing I have to say that is ugly about the stock frs are those god-awful tails, I'd personally go for the Red Tom's or some buddy clubs, or if you're feeling adventurous, the Crystal eyes, but I don't know how high quality those are.
I can't see how flush your wheels are but if you're not planning on getting thicker wheels, I'd go for some wheel spacers to put them flush to the fender, it makes look a billion times better.
New hood and trunk lid spoiler: now granted this is a gonna be over 2k total between paint and parts, but VIS racing has a carbon fiber trunk lid spoiler that replaces the trunk completely, as well as a vented hood, both if they were tastefully paint matched would look sick as fuck. Those are what I'm doing anyways!
And lastly, at least in the looks, department, are a shark fin antenna or shorty antenna, and also some springs! Make that bitch aerodynamic!
Good luck man, keep us posted on what you do!
'14 Firestorm FRS Build Thread:
http://www.ft86club.com/forums/showthread.php?t=71248