Hey Man, hows it going?

Ok, as for your questions!

You can put your speakers in the door, when installing them make sure your window is down, because if you put them in and your windows upwhen you try and put your window down they might hit...

Honda's usually come with 4" inch speakers, but you can fit 6" cos i have Boston FS-60's in my front

With your sub, make sure the box is correct and that your sub is an enclosed sub not free to air...
Most people buy $250 Pioneer/Alpine subs and don't realise they are free to air so they put them in a box!

Also, the dimension's on the box packet are usually the best..
Try and go to an installer and ask them what they think!

AS for the amp under the seat?
I was going to put mine there but my installer told me otherwise!
This is a common area for people to put amplifiers but the problem is heat and make sure if you put your amp there that the exhaust is not on the drivers side either! (underneath)
If the exhaust is there your amp will cut out all the time because it is hot...

As for buying an amp/sub for $600
Well there is an Alpine 4 channel that goes for $220 (i think) they are pretty good for what you pay
And sub, maybe a Pioneer or Kicker Impluse!

I would recommend you to go JL but you wouldn't have enough money to get the box made...

Overall, try and stay away from Japanese brands when coming to amps/speakers/subs!
The best brands are european and american!
Americans make the best subs (JL,Kicker etc..) and Amps i only use and recommend Audison (Italian)...

Speaker wise, again i say American it's just the quality they have!

Anymore questions please do post


Jason