Hi, So i acquired a 2012 EX35 AWD and was wondering what options I had, I've looked on here and the facebook group and this is what i've gathered. Please correct me if i'm wrong

Intake- Only drop in filters.
Exhaust- Axle back of G35/37 Coupe are bolt on.
Lights- I'm upgrading reverse lights, fog lights, high beam, low beam and parking lights (next the the high beam bulb?) with LEDs

This is what i need advice on

Saw mention of 100 cell high flow cats. any info on these? brand? bolt on?

Intake-any g37 intake with minimal modification will fit

Exhaust- axle back, and y pipe are the same, not sure about mid pipe. I have qx50 so mine is little longer, but since yours are shorter so i think... coupes and ex use same one.

Lights- Just so many options....

I've ordered all the required LEDs. I swapped my mufflers for that of a G37s today but the sound difference isn't that great. Thinking of doing a res delete.

Not a fan of resonator delete, but hey. it is your car. Good luck.

I'm not keen on doing it either but i even swapped the mid pipes from the g37 and it still sounds like a cyl.
At this point i can either slap on a Topspeed axleback or HFCs or go to a local shop to do a full custom setup

Changing hfc and bigger piping y pipe will increase sound significantly...

Just picked up and installed a DC Sports SRI4205 Polished Short Ram Intake System last night. It's made for the G35 with the vq35hr but everything bolted right up perfectly. Looks great and sounds good with a slightly more audible "woosh" when you tap the throttle and a pleasing almost blow off valve like air release kinda sound when shifting up from high rpm.
Next up is taking it to a custom exhaust shop for a high flow cat and then to a tuner.
https://imgur.com/a/Dcsu8W7

These are noise producers. You will lose few horses with short arm intakes...

Well it's not a short arm in a literal sense, the filters themselves run right up to the stock air intake runs that hook up to the stock air boxes. I don't know if that'd make it any different than ram air intakes. When I think of ram air intakes I think of shorter running tubes to the throttle body but correct me if I'm wrong as I'm still trying to learn this stuff. I got them to try to just increase the total air intake.

Yes, they are considered short arms. Sitting under hood and sucking hot air. Hot air=power loss. Stock intake is more shielded from hot air and it is drawing more cold from outside. Heat soak with this kind intakes terrible during summer months. I had R2C intakes and they did not perform too good anything above 70f.

So the kit I got didn't include any heat shield, so what you're saying makes sense. If i were to rig up some heat shields to keep the heat from the engine somewhat away from the intakes, and with the filters already positioned in front of the preexisting air intake ducts, would it help mitigate the issue of it pulling the hot air from the engine while still pulling more air than the stock setup?

maybe more, but it is much hotter. Hotter means less dense, less dense... less power you are making.