Injen expertise eh?
Then why did my Celica GT-S run like s*** after I installed my Injen CAI on it.. And they refused to take or respond to my calls about it even though I left them messages asking why the car was acting that way.. It ran perfectly fine stock but not with the CAI on it... Just saying that just because it's a brand name company doesn't mean it's great. Think the opposite of APC... For all the crap stuff, they do have some good things.. Injen's the same way, just opposite.
Anyways, I have the eBay CAI. The thing looks the same as any Injen CAI. The only difference you're going to see is that you can get the Injen one in other colors.. or perhaps the polished one is a bit shinier..
Toss the filter that comes with it and go to
www.ajusa.com and get K&N cone filter part number RU-4450. It's the exact same size that comes with any other CAI you get and then you have the K&N quality filter. Shipping may take about three weeks though, but it's worth it since they have the absolute best price and free shipping. The rest is just pipes honestly, and there's NO difference at all between the Injen and eBay cold air intakes' pipes..
I don't see why you can't just disconnect the secondary pipe in the eBay/Injen CAI and attach the cone filter directly after the MAF unit.. that's if you're worried about the rain.. You could even get yourself another filter or put the filter that came with the eBay one on there temporarily.. It really shouldn't hurt anything.
The coolant tank takes a whole 30 seconds or so to relocate. It's really that easy.
I voted Injen just because of CAI.. but my verdict is eBay cold air intake (got mine from Trivision Auto) and a K&N cone filter. Costs after shipping is about 90-100 bucks. Save the extra money you save and buy something else with it. All these people can go ahead and say that Injen has all the product knowledge and stuff so they will pay the extra money.. and if that makes you feel better that you dumped a grip of cash on something with a sticker of a company on it, then more power to ya.