I just installed my sub. 2009 jetta TDI manual. here is a pic of where to run through.
I am assuming they are or sub woofers, so I'll add some other things I learned and pictures that might help you out. if I'm wrong about the subs, maybe someone else will find it useful.
you remove the battery. then follow the wiring harness back to the firewall. there will be a grommet there. the grommet will have some nipples on it. grab one and hack it off. a pair of scissors will do fine for this.
you will have to go on the inside and remove the black plastic panel that is above your pedals. 6 or so torques. 10 or 12 bit side. again find the wiring harness and move the sound deadening material out of the way.
don't bother taking off the kick panel where the hood release is. it's a PITA and unnecessary.
then back on the outside of the vehicle again push a length of 20 guage wire through the hole where you removed that nipple. tie it to the 8 guage wire and pull it through. I used 4 gauge wire so I know it will work for four. let me know if you have any other questions.
I'll put in a couple more pictures. they might help.
I had a spare post on the power buss so it was really convenient. lowes has a lock bolt that will fit right on there.
there is a ton of room for wires in there, and the battery really hides everything when you are finished.
I ran mine under the panels by the doors. remove and install is a cinch and ir's pretty much a straight shot to the trunk.
