Mirror caps (carbon or black)
Hood Vents (carbon or black)
Side Gills (carbon or black)
Since price will double or triple on an exhaust and you did mention that being an issue, here are two affordable exhaust systems
Remus - $1200 I think you can find this exhaust
Megan - $500 You can find this exhaust
I've had Remus products, they are great for the price. I've never owned Megan but can you really go wrong with that price?
Again, if price is any sort of issue, you can get some badass wheels much cheaper.
Velocity Motoring (VMR) - makes great wheels, Ive beat up a few sets of these and they take it like a champ.
Varsstoen - These guys make nice reps of Volks and BBSs. I ran a set of the TE37 reps they offered on my my 08 and had no complaints.
Coilovers are over-rated for this car UNLESS you are a track head and really are capable of driving your existing stock set-up to the limits, you probably should not waste money on Coilovers. Most guys drive their cars on city streets and their cars see maybe 1-2 track days a year yet they think they need coils. Its insane.
Here are two other options for you...
H&R Springs - you can get a set for around $300. Gives you a nice drop, increases cornering. But you will feel a little more bounce at high speeds (120-130mph) when hitting bumps.
KW Adjustable Spring Sleeve Over Kit - This is just released from KW and should be more than sufficient if you are looking for an adjustable drop. I think they run around $800.