hey, well my plan is to use an hdmi to composite converter because my car only accepts RCA(composite) input. Have hdmi from phone to this, then this to my car's input. Resolutionwise, my screens in my car are 800x480 resolution, so having high def from my evo really isnt an option.
HDMI to 3RCA AV/Composite S-video Converter for PS3 DVD - eBay (item 190469938705 end time Mar-18-11 02:25:04 PDT)
Then, i have to be creative with my power supply (lots of interference for some reason if i use the ac to dc inverter in my car with the hdmi converter above). My solution is to convert my car's 12v to 5v dc using the innards of an old cigarette lighter to usb adapter (the usb has 5v output). alternatively, you could take an easier approach and buy a dc regulator like on this page, which might be cleaner to install and maintain.
Multi Level DC-DC Regulated Adapter ( 1.5V-12V) with Switch and 100-240V worldwide AC to 12V DC converter
The way i have this set up now, is that i have the hdmi converter and the power supply mounted behind my dashboard and already hooked up to power and inputs of my stereo. It turns on and off with the car, which was easy to achieve by tapping into one of the "ignition 12v" wires already feeding my stereo. this prevents battery drain.
My only hurdle now is figuring out the best mounting solution that would allow easy (clip in/out) access and hold securely (apparently the hdmi is temperamental on this phone).
As soon as my next rounds of exams comes up in 2 weeks, im going to spend the weekend designing some sort of car mount that will do all that and also have usb power to also charge the phone as it will be a busy little bastard.
again, this is to feed the tv's in my back seats and to allow for easy streaming of online radio without having to fiddle around with a stupid 3.5mm headphone jack. NOT FOR TV WHILE DRIVING! although totally possible if your stereo is set up so, it is not my intention to drive off a bridge while watching episodes of archer. All connections will be on the bottom part of the phone and i wont have to spend 10 seconds getting the damn thing set up each time i get in my car(it doesnt sound like alot of time, but its enough to deter me from using my phone like this).
thanks for the read, sorry for the long post! (also, the day i get the fullhdmi app, i will do my best to get a video on youtube of the entire set up).