Does anyone know where to get the factory under trays for the Evo X, including the front, rear, and both left and right?
Also does anyone have the part number for the plastic piece that goes from the front splitter to the front engine under tray.

 

Any Mitsu dealer can order them, or call STM and have them get them for you.

 

I've had to replace this a couple of times, from the local Mitsubishi parts department.

Make sure you get enough fasteners. If you tell them "I want all the fasteners to go with it" the people at the parts counter don't have any guidance but a drawing from the manual, and they're likely to give you four (4) fasteners. They showed it to me, and I can see why they'd make that mistake.
I really needed 15 fasteners.

As I recall, they cost less than $1 each, and were tiny expense compared to buying a 3rd undertray.

EDIT: I just re-read that you want 4 pieces of undertray, and that could be 30 fasteners.

 

Honestly, I would look into getting an aftermarket under tray. The factory under tray is prone to cracking and breaking if it hits anything. I've gone through two, before I decided to upgrade to a two piece WTF under tray. It's held up really well. I've done a year of rally cross and winter driving with it and it hasn't cracked anywhere.

 

Have you heard anything about the ssp undertray? Is it worth it?

 

It's good too. I know a couple people who run it. It's all aluminum so it's going to be heavier than the WTF undertray, and more expensive also.

 

WTFTuned used to sell an aftermarket undertray that was awesome - if you're needing to replace may as well minorly upgrade where you can!

https://www.wtftuned.com/collections...ody-protection

Looked awesome on people I've seen with it installed - easier for oil changes too.