What are some of your "must-have" mods/accessories?

There's a thread for that already and there's over 19K comments in it. No need to start a new thread: What did you do to ur Gen III Prius today???? | PriusChat

 

Would not hurt to have a less cluttered thread with fresh content and easy to find.

Most of the images are broken in that thread anyway.

That being said some of my best mods and accessories are the following.

Red Bullet

Lithium HV battery

Magnaflow catalytic converter

Ganador Muffler

Rebuilt ICE with 2015 pistons/rings

Blitz WAI

JET Performance MAF sensor

Aluminum skid plate

Millercat catshield

TPMS monitor

Rear wiper delete mod

I could go on and on but lets see what else we got out there.

 

There’s some fragile looking, exposed wires going into top/front of the under-hood electronic control module (near fuse box), and there is a cover available:

Question in engine compartment | PriusChat

Oil catch can is a good one too. The mother of all oil catch can threads is linked in first line of my signature (on phone turn it landscape to see signature).

And conversion to spin-on oil filter:

Spin on oil filter | PriusChat

 

There's also a Lexus CT200H cover that you can get that fits over the inverter and makes everything look cleaner:

 

Rear Hatch Lights like this: Toyota Prius 2010 - 2015 Rear Hatch Trunk Luggage LED Lamps
I wired mine in with a switch cut out in the trim panel. By default I think it always turns on whenever the hatch is opened.

Thread with more details here: Rear luggage light connector? | PriusChat