Can the bulbs/LEDs just be replaced, or are they soldered in? Are there any good reverse glow guages that will fit an '04 I35?

 

You should be able to just replace the bulbs with brighter or different ones to brighten it up. Someone on here posted a link to a page that sells LED bulbs made specifically to replace the existing bulbs in your guages without any mods. I will try and find that link and then post it here for you.

 

I35 gauges are supposed to be EL, so replacement of bulbs and/or gauges is going to be difficult. You have tried adjusting the dimmer switch...right?

 

Oh, sorry man, I didn't realize they were EL. My fault. Dissregard what I said earlier.

 

How exactly does this complicate things?

 

EL = Electro-Luminescent. Think of flat panels of material - almost like laminated paper - with electrodes so that once electricity is applied to them, they glow. I haven't looked behind the gauges in this car, but according to the manual, they're EL, which would mean that the gauges are probably pretty heavily integrated, with a lack of replaceable bulbs.