Upgrade the suspension. Lowering Springs (TRD or Hotchkis, that way you won't need to replace
your shocks/struts right away), Rear Sway Bar, and stickier tires (if you can afford them.) Your tC
will handle soooooo much better.

If you have $$$ to burn, go with CAI and/or exhaust. You tC will sound better but the performance
gains are VERY minimal. Tint makes the car look clean. Lastly, get rid of the OEM horsewhip antenna
and get your self a Honda Element one. Looks the same as a S2K antenna but is usually $5 cheaper.

 

coilovers. why buy springs if there will be snow around you. you'll spend more but when time comes you can raise it up no problem. as far as the CAI, they all do the same thing why spend 250+ on a brand name, unless if ur going for looks than yea go for it. heard that the headers dont do anything for the tc. anything u do dont look at what others have to say cuz its your car in the end and what u like