Car Stereos: Where to put hole in Firewall?, rubber gromets, alpine system

Question
QUESTION: Hello,
Just bought a 2001 Lincoln Continential  a few weeks ago.  It has the factory installed cassette.  No cd player and it is not the Alpine system.  I installed a 2 amp set up in my old ZX2, so I am a bit familiar with wiring, amps, grounding etc.
I can not figure out where to put the amps power wire through the firewall.  There seem to be 2 rubber gromets to the left of the brake pedal. On I believe may run the hood release.  When I open up the hood, I can not find where the wires come out (the other side of the gromet) for the life of me.  I was wonder where the best place is to run the power wire through the fire wall to the battery.  Once the power wire is in, pulling out panels and getting it to the trunk should be easier.  I bought a new Pioneer head unit which in on the way and have a US Acoustics USX 4085 4 x 85 amp.  I plan on installing Alpine 6.5 Comps (Crutchfield say these are the only 6.5 which will fit), 5x7 Alpines in the door (powered by the head uint) and put my Polk Sub in the trunk powering it by bridging the 3/4 channels in my amp.
Sorry for this lengthy explanantion. I just wanted ot have all the bases covered before I started popping door panels and taking apart the dash.
Thank you in advance,
Mike

ANSWER: Mike, The best place I have found to put the hole is just over the pedals.  Look on the inside above foot pedals, and find a spot where a cable or wire is going through.  Once you see where a cable is going through, look on the engine side, and see if you can make a hole near it.  If so, you can drill a hole an 1/8 inch larger than the diameter of the wire.  You will need to buy a grommet for that hole, and it will seal off from the inside and outside.  Hope this helps, Scott

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2001 Lincoln   QUESTION: Thanks Scott,
I forgot to ask the first time.  Once I install the amp I want to install components up front.  The factory grill is in front of the armrest at the same level.  If the woofer goes in the factory location, it it okay to put the tweeter below the woofer?  I do not know if the picture I am attaching will come through.  But I want to put the tweeter below the factory grill, in front of the arm rest and just above, the storage compartment in the bottom of the door.   The Rockford Fostgate speakers I am looking at will allow me to increase the dbs on the tweeter if need. Would this placement be okay?  
Thanks so much in advance,
Mike

Answer
Mike, You can place your tweeters anywhere, but there is a method to where they are placed.  Bass sounds are omni-directional.  That means you can put a subwoofer anywhere, and the sound will be the same.  The higher the frequency, the less omni-directional the sound is, so tweeters are very directional.  The closer you can point them to the drivers ears, the better the highs are going to sound.  So, you can mount them lower, but they will sound better higher.  Keep at it, Scott