Newbie needs tips, advice for installing subwoofer in 08 9th generation corolla

[driving90]

Right now, i'm interested in putting a sub into my 2008 corolla. I did the head unit a few months ago and it was pretty easy, so i figured, why not get more punch.

While messing around behind the dash, i found a gap in the paneling where i can route the RCA preouts to the sub, so that's done, but there's still a few questions I have before I jump in.

1) How do I route the power cable from the battery to the trunk? Do i need to drill a hole in the firewall or is there an existing gap I can use?

2) I haven't taken a good look yet but is there any bolt in the trunk that you'd recommend for grounding? And also, when I do ground it, all I need to do is sand down the area around the hole to the bare metal and tap the cable on, right?

3) I'm looking at subs in the range of 6"-12". When my friend installed his (rather small) powered sub, he drilled holes into the car and secured the sub box with a bracket that was included with his sub. If I get a sub that's weighs heavy enough, would I still need to drill holes & mount the brackets, or would you say I should be fine not doing that?

[anoiel]

1) there is a hole in the firewall that you can route the cable through, just look for all the wires that are going though the firewall and you should be able to get it through there.
2)to ground the amp just sand a part of the trunk and put a screw though it. as for preexsiting bolts in the trunk i dont know about that.
3)if it is heavy enough no it wont move around but if you are going for one sub you might want to tie down the box since it most likely would move around while you drive.( ive never had the problem since all my box's ive had have been real heavy)

[syang]

another good reason to bolt down your sub box and amp is if you ever get into a car crash. (i'm not saying that you will) they can become potentially lethal projectiles. there are horror stories out there that people get into car crashes and was killed by there sub boxes and not buy the crash.

[frojoe]

-The hole in the firewall is often near the drivers side wheel well.

-The back seat seatbelts can be good bolts for grounds, but make sure you tighten them up well again. And yes, just sand down to bare metal and use a ring terminal.

-Aside from possible rattling if you don't bolt it down, as the above poster mentioned, securing your sub is a matter of safety.