This is what I did with washable Fram filter that unlike the K&N types needs no oil or special washing fluid. I got all the ABS Plumbing at the local Lowe's Home Improvement Store.
The filter is can be a little hard to find. I bought the only one they had at Walmart and the other I ordered on the internet. I have one on the Mercedes and other one on my Volvo Diesel.
Washable Air Filter and Intake Mod , With Larger Breather
Washable Air Filter and Intake Mod , With Larger Breather
In the below thread towards the end is a similar intake but it has a larger non-washable Paper element Fram Filter; if you think there is room for that.
Also in that thread is another thread I did testing the Hot Air Intake. In actual fact the only time hot air builds up under the Hood is when you idle. Ounce you start moving that temp drops quickly to nearly the outside temp; even in City traffic.
But, that is with no sort of Belly Pan under the Chassis.
any real benefit to a K+N filter