BMW 318i

http://www.turnermotorsport.com/html/index.asp thats a website for upgrading different bmw's

You could try www.demontweeks.co.uk

depends what your looking for, you should be more specific.

just keep it simple . good regular oil changes. change the airfilter. that will free up around 5bhp. performance exauhst. it all depends how much money you wanna spend tho, theres loads of things you can do. or just sell the one you got and buy a 325 or 330. not many cars can keep up with them.

a 318 is a great car to do upgrades to. My first bmw was a 318is. Some things that won't hurt your car upgrades is of course a cold air intake system such as a afe or dinan, just dont use an oiled filter they can harm your electrical systems I just don't trust it. The other is performance programing from dinan or conforti. Both are great programs to increase accleration and horse power and get rid of that speed limiter and raise your rev limiter. I mean you could go on and on about what to upgrade. To put it simple it depends on your budget and what your looking for out of your car. If you would like any further help with these upgrades you can find me at bavarianpower.com check out the site and email me their and I'll help you out further.

what kind of upgrades? are you wanting to race it?