AEM brand intake with a K&N brand air filter. its $200-300. been a while since i bought mine. should only take about an hour to install. its definitely step one in engine mods. I had a cold air intake on my civic for a few years, which works great in the winter. however, I re-assembled it as a ram-air intake recently due to fear of hydrolock. hydrolock is if you drive into a puddle deep ehough to reach your air filter. in which case, you will suck water into your filter and and totally wreck the engine. i dont think its worth the risk. i would recommend ram-air (short pipe) over cold air (longer pipe extends to wheel well).i agree with the other guys though. dont drop too much cash into a honda civic DX... if you had a EX or SI, different story. the B-series engines have much more potential than our D-series engines. you might as well keep the thing inexpensive and fuel efficient. the way it was engineered to be. an upper rear strut bar is a cheap step into suspension upgrades. it will obstruct some of your trunk space though. i've found it helps a lot with body roll on my civic dx sedan. i bought a no-name one on ebay for like 20 bucks. geart buy. simple install.good luck and keep it classy (no noisy muffler or ridiculous wings).