if it recommends the direct wire from battery and you're planning to use the internal amp, you'll have to seriously consider running that wire...

i can't tell you what i would do since i don't have to live w/ your consequences.

for me, it was a no brainer since my power draw was going to be so low (internal amp off).

 

I have another question. Since I plan to add an amp later, should I run a larger guage wire from the battery to run the HU and then attach the amp to it later (probably a small amp to power 8" sub)? Can I do that? what can I use? Distribution Block? what guage wire then? will 10 or 12 ga enough? sorry for all these question. it's my first time installing anything. TIA

 

run the wire from the battery when you install the amp. that way, you can size the wire based on what you're installing. and you'll only need a distribution block if you're doing multiple amps.

regarding wire size -- i find this guide to be very effective:
http://www.bcae1.com/wire.htm

and this calculator will 'run the numbers' for you, and tell you what gauge to buy.
http://www.bcae1.com/images/swfs/systemdes...gnassistant.swf

 

Can I use the stock changer with the 9827?