I bought a 2019 Z. There is no under hood insulation. Wondering why as this car gets real hot under the hood and could lead to paint failure in the future. Do older Z's have any insulation ?

Maybe a cheapening move on lesser optioned cars, I've noticed some late model cars with none as well. High perf ones may be intended to let the driver hear the engine more. My Versa is optioned up but even so still a crackerbox car and no insulation on it. And there are always the miss cars on the assembly line that miss this or that minor part when the assembly boxes run out of part to have to be changed, that line pretty much stops for nothing. The stream of cars is never 100% identical in all ways.

Question is, do you want the heat to attack the paint, or held in by the insulation to attack the wiring and rubber and plastic parts under hood? Always the tradeoff there.

"Quote from amc49" Maybe a cheapening move on lesser optioned cars, I've noticed some late model cars with none as well. High perf ones may be intended to let the driver hear the engine more. My Versa is optioned up but even so still a crackerbox car and no insulation on it. And there are always the miss cars on the assembly line that miss this or that minor part when the assembly boxes run out of part to have to be changed, that line pretty much stops for nothing. The stream of cars is never 100% identical in all ways.

Question is, do you want the heat to attack the paint, or held in by the insulation to attack the wiring and rubber and plastic parts under hood? Always the trade off there.
You bring up a few good points. 1st Im going to check with my local Nissan dealer on the insulation. 2nd the paint on the hood is not under warranty. Everything else under the hood is so as far as a trade off I would rather have the under hood insulation. I live in Florida and between 95 degree days outside and well over 200 degree temps under the hood just simple rain can stain the hood as its drying. I appreciate your feed back amc...

You will be able to add the insulation but you may get a WHOPPING surprise when you price it at the OEM, they tend to waaaaayy overcharge for incidental parts like that as they are often used only with major body work that the user can bury the cost in.