I'm probably going to regret this when one of you buys something I was watching but im a giver so here we go. Normally when you search yahoo using Import Monsters page you get a fork load of brake pads and lines, LEDs, boss kits and other crap we dont want
Example
There is a work around for this. First thing is to go to the yahoo japan auctions page and then the automotive category. Heres a handy direct link. If you use chrome like a sensible adult it should auto translate it for you, if it doesnt click this icon in the top right
If you dont use chrome you should get chrome.
From here you can search in the bar or click a category. When searching I use model code such as BG5 or GC8. STi has some cool results too.
You'll be presented with a page like this
But its still full of crap, whats the point of this DIY??????
Send your attention over to the side bar
Pretty obvious what the first one does! The second option shows the newest auctions first, this is handy as most of the crud is old ads that never get taken down so New Arrivals can show some good bits.
Theres that JDM hawtness we all want. Now your probably wondering how the heck do i buy this awesome stuff. Read on:
Copy the URL from the yahoo ad you want to buy
And then load any random item from Import Monster, I usually just grab something from my watch list
And replace the section after the "=" with your copied yahoo url and hit enter
Assuming you did it correctly IM should reload with the item you wanted ready for bids or shipping estimates. Now get upset about how you cant really afford it and add it to your enormous watch list 
