i insullated mine, it was easy. I used to different sizes to cover the pipe coming off the condensor going past the engine into the car. I also used plastic ties to hold it on. I noticed a small differences in the coldnest of the air inside the car. If you want pics i can take some.

How long did the install take?What kind of tools did you need?Does anyone have pics, or an electronic copy of directions

the butterfly valve opens when the motor is cold to suck in warm air from the motor, and when the motor is warmed up it closes. i also found documents on how to remove it, but cant find them. i think i got them off the newcelica site.

i got my 40 series for 54 bucks. and that included shiping. you have to do your research before you bid on these. Make sure you are getting the right one for your car. here is a link to his seller page. http://cgi6.ebay.com/ws/eBayISAPI.dll?ViewSellersOtherItems&include=0&userid=whosplaying&...

sorry i forgot to post it. I'll send my self a reminder email to get it. the person that created the "how to" said it gave 1 or maybe 2 horse more. And you can always put the flap back....again sorry for having such a forgetful mind...

dmitri whats your car sound like with no muffler. I have thought about doing that, but we have a lot of jerk cops were I live.

There is a way to remove the air flap inside the air box. When i go home I'll post the link. It was off a celica website.

i do it all the time.

thanks

If anyone is interested TRD has come out with a short shifter fo the matrix, that they say will fit the vibe.