Stock impedance 4 ohms. I just walked into my garage and dug out the stock speakers.
Clarion model: nz409
Nope it sticks out a half inch though I have thought up a few solutions for this it comes down to fiberglass or heat gun either way my dash is gonna come out.
I'll look into the noodle wire ironic that I've never heard of it as I was on a robotics team at one point

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I've just been using the same 16 guage speaker wire from outrageous audio since before I could drive the cars I worked on. I think it runs me like .30 a foot and I bought about 120 feet of it back in the day. I've used it in door speakers and 10" subs in the back of my firechicken and after two years they're holding up beautifully. Comes with a nice corrosion resistant coating on the strands so even in a hatch that always leaks I'm never building resistance.
I just put a jvc in my n/a sprint most of the time was spent ripping out the previous owners shotty wiring job in the end I hate that it doesn't have a USB port but hey can't complain when it's all free. The jvc fits perfect no depth issue. I bought a portable charger because he also shorted out the cig lighter and blower motor speed control that's tomorrow's headache.