personally i'de get rims before header(if i had hubs)
-Red Wuken
if i had hub caps id def get sum nice rims before a header anyways.
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You just put a new suit on your ride. Now you have to put the right shoes on. Just like igotta5S-FEturbo said, no one is going to see the guts unless you spill-em. Plus that can be done later.
Like everyone else, I'd say go for the rims first, but they're going to cost you considerably more than a header, because low profile tires for 18" rims are expensive! You'll probably end up paying close to another $500 for some mediocre tires for your car, and even more if you want some high end tires. If you've only got the $500 now, I'd say save it for either an engine swap eventually if you really want performance, or save the money and get rims once you've got the money to buy tires for them too. Realistically, your ST might gain 5 horsepower max from a header, but it may be even less than that, and chances are that you're not going to feel a large increase throughout your entire powerband.
New Toyota project coming soon...
do any of you know where i can get a carbon hood ?