Hi, I'm Mexican sorry if any of my writing is wrong. I'm from Acapulco, mexico

I have a 2004 Roadster N/A, from sometime to date is has been giving me problems.
I have a pair of pioneer 12" in my trunk i dont know if this has something to do with the trouble.

It started a couple of months ago with the indicator light failing only the right one, sometimes it worked sometimes it didn't until it stopped working, the right light brightness is lower than the left ones and the signal of the problems in the dash is sometimes on and sometimes off, also the car kind of drained a battery but first started with me turning the car on an every electrical thing kind of getting crazy the spoiler started going on and off. I

But the main problem was two days ago that a friend of mine tried to charge his cellphone with and adapter, the one that goes to the lighter, and the phone turned off and wasn't charging so he told me to try with mine and the same thing happened, so what happened is that both phones completely died, they kind of blew up hahah, not working anymore, my guess is it has something to do with electrical shocks or instability or something in the car, any one has had an experience like mine? how can i fix it myself or whom can help me know what is wrong