So I know from dealing with my nav screen issue there's not a great deal of support for the 04-08 RLs and the fact that there aren't many means parts are hard to find. Question is, is there a list of parts that are interchangeable with other models?

I saw a post regarding swapping in intake manifolds from a 3rd gen, and a few references for some lighting items, but what else can be sourced for my car by looking up a different model?

 

My search on the nav screen OEM part # turns up a few low cost $150 screens, if that is the issue with yours, versus a new one from the dealer for $2331.61.
Navigation System - 2005 Acura RL 4 Door RL KA 5AT (acurapartswarehouse.com)

Center Dash Information Display Screen for 2005-2012 Acura RL 39810-SJ – German Audio Tech

05-12 Acura RL Front Lower Dash Navigation Display Screen 39810-SJA-A011-M1 OEM | eBay

 

Just got a junkyard nav screen for 15 bucks and a replacement DVD player for the trunk for $10. Hopefully they'll give me some functionality, but I still want to replace this with an aftermarket solution with better maps and navigation as well as backup cam interface, probably a second cheap android head unit tbh.
Chesterfield auto parts at Fort Lee for those curious...those were the prices before the 20% veterans discount...best part was that someone has already taken the head unit and dash trim, so all I had to pull were three screws for the nav screen and four for the DVD player in the trunk...took the vin down for the codes...need to figure out how to find them on my car...

 

Let me try to clarify with examples...

On both of my trucks, a 99 S10 and a 98 F150, I was able to recognize that parts were interchangeable between different models, and that even with the same part numbers, the price changed based upon the name of the vehicle. 2000 expedition brake pads calipers, rotors and brake booster were an upgrade and direct swap for my 98 F150, and if I ordered them by part number instead of typing in 2000 expedition into the search engine, I saved an average of 20-30% of the price on the parts. The same went for the Lincoln Navigator which used most of the same parts as well.

With the 99 s10, I swapped in 2000 blazer brakes in, to include spindles for an upgrade. Same parts as a GMC Sonoma, or a jimmy, or an Isuzu Hombre of the same year range.

What I'm asking is, are there Hondas or Acuras that will interchange with my RL. I've noticed the brakes aren't the best, and would love an affordable upgrade. I'm sure the engines weren't unique to the RL after all. If I needed new engine and drivetrain parts, what vehicles could I source? I got lucky with the junkyard nav screen, but it was literally the only RL in the junkyard, so what could I have pulled a screen from as an alternative, for example?

​​​​​​I recognize that I just rolled in, but I'm hoping we have a little more support for this platform that I just haven't found yet. Would be nice to add some nice things to the car, which is nice to begin with.

 

The car as a whole has a lot of bespoke parts. It's not a twin under the skin to anything else. If that's your hope, you're out of luck.

That said, a lot of individual parts are identical or similar to other Acuras and Hondas. I think the whole engine is basically identical to some other model(s). I apologize for not remembering, but it might have been the later TL Type S. The transmission was also used on some Odysseys and Pilots. I had to replace the interior cylindrical fan-blade assembly for the heater, and when I pulled it out it looked like an Accord fan might have been easily configurable to fit in for about a quarter of the priice. The nav system shares its DVD and basic guts with several other Honda and Acura models; this info is easy to find on eBay and other places where the DVDs are sold used.

Hope that helps a little.