is there a diagram or anything that shows where you should NOT drill in ur firewall. like for runnin ur powerwire. i have heard of people damaging hoses and stuff...
i would pass the power wire were there is already an opening thru the firewall...thiers normally a black rubber surround with wires being fed thru the firewall....its in all the cars ive installed systems in...
find the dust boot that all the wires are going through and take a razor and make an incision, just enough to get the power wire through and you should be able to get it into the car from under the steering wheel column
thats what i did reloaded and that works good im just worryed its gona leak around there and that would be bad because all my other wires are around there and that blows. but it slides right in there my car is weird the battery is on the right