You got it right. MB's will fit with no problem. I bought the Autobahn's 5 1/4 component there 120 watts RMS. They are awesome. I have them hooked up to a 85 watts rms amp, 2 x 10inch 600watts RMS Audiobahns and running off my head unit
Here's directions to the back speakers.
First of all... Gather your materials. Other than some basic tools, you will also need a soldering iron. Also, the rear speakers are 6.5" NOTE: Installing speakers yourself will void the warrenty that you get with the aftermarket speakers. Professional installation is recommended. I did some things I wouldn't recommend doing to your car... more on that later.
1. REMOVE THE BACK SEAT. Lift up on the seat bottom to remove it. Next, fold the seat backs down. Third you will have to remove the seat trim between the seat and the door. There are 3 places that the trim is attatched. There is a hook at the bottom, and at the tops. There is a clip in the middle. First, pull the trim down to unhook the bottom. Next, grab near the middle clip and pull. Last, to remove the top clip, lift the trim up and wiggle it around until it comes loose. Repeat on the other side.
2. REMOVE INTERIOR PANEL FROM REAR DECK. You must remove this panel because the speaker grilles do not come off, and you will not be able to get to the speakers otherwise. First you will need to remove the child seat anchors. Get a small flathead screwdriver to pry up the plastic covers. Next, use a socket wrench to remove the bolts. Next, you will need to pull the front up. It is held in place by a few plastic clips that go through the metal deck. Pull up on the front to free it. Next, you will notice that there is foam between the interior panel and the metal deck. This is now holding everything together. It is easiest to peel away the foam from the interior panel. Last, unplug the brake light. You will see the wires in the trunk. Lift the interior panel up a few inches as you pull it towards the front of the car.
NOTE: You will notice that there are seatbelt holders attatched. These will slide with the panel, and there is no need to disconnect the seatbelts. Now you can simply lean the panel where the seatbacks used to be, and you will have plenty of room to work.
NOTE: This is an EASY method. You will not be hardwiring the new speakers. You will not rewire the car, and you will NOT be able to use the factory speakers any more.
3. REMOVE THE REAR SPEAKERS. There are two screws on each side holding the factory speakers in place. Remove these two screws. Okay, now remove the speakers from the car. Lift them up through the deck. On the driver's side, you will notice an amplifier hanging off the speaker. Unplug this and remove the speaker. On the passenger side, unplug the speaker. Okay, now you can go inside. Now you will have... Your two new speakers, and your two factory speakers with the amp hanging off one.
4. TIME TO OPERATE. Alright... first lets start with the passenger side speaker. You will notice that there is plug attached to the bottom of the speaker. First, remove the factory wiring from the contacts. Now, take a Dremmel or similar tool and cut the plug off the speaker. You want the entire plug to remain intact. Now, with a soldering iron, solder the contacts of the plug onto the contacts of the new speaker. Be sure to keep the + & - on the correct side. Okay, now your rear speaker is done, and ready to plug in, but you're not ready yet....
5. TIME TO OPERATE: PART II, THE DRIVER SIDE. Okay.. now you will notice and amplifier hanging off this speaker. There will be 3 screw on it... two on the side, and one going up towards the speaker. This is the only screw attaching the amp to the speaker. DO NOT unscrew the other two screws. Detach that and then cut the green and black wires as close to the contact point ON THE SPEAKER as possible. DO NOT cut the wire off the amp. Okay, now solder the Green and Black wire to the speaker. Now you will be able to plug the factory wiring back into the amp.
NOTE: I could not find a way to attach the amp to my speaker. I used duct tape. This is not recommended. Also MB QUART makes an adapter to install rear speakers. You will notice that the whole in the rear deck is square. The adaptor makes it so that the speaker can sit correctly. I did not use the adaptor. I drilled a hole through the rear deck and screwed the speakers on.
6. REINSTALL YOUR NEW SPEAKERS. Simply plug the factory wiring into the plugs on the speakers. Attach the speakers to rear deck.
7. SPEAKER GRILLES. Okay, the first thing I decided to do before putting my car back together was to make the rear speaker grilles removable. If you notice, the grilles have plastic posts that go through the interior panel and are held on by toothed metal washers. I cut through the metal washers with a pair of heavy duty scissors. Then, I got nuts that were the same size as the posts. I twisted the nuts down the posts to thread them. After you thread all the posts, you can but the speaker grilles back on the panel and screw them on. Obviously, you don't have to do this, and it won't help you.. but I like it better that way.
8. PUTTING YOUR CAR BACK TOGETHER. Okay... now that you have everything secured, it's time to get your car back to normal. First, reinstall the interior panel. Slide it back up. Push back and down on the panel as you put it in. Then, press the clips down in the front. Reinstall the side trim next. It needs to go in BEFORE you put the seat bottom in. Then, fold the seat backs up, and install the seat bottom cushion. Turn the radio on, and enjoy.
the front speakers
My A4Q is the non-Bose, standard-stereo US version.
What's currently there: each front door has a 4" driver mounted low, with a 3/4" tweeter mounted high and crossed over with a simple capacitor. Speakers are made by Nokia.
Interestingly, the 4" driver on the driver's side is different from that on the passenger's side. It's a dual-voice-coil design, with the second coil fed from a seperate pair of wires. The reason for this is that the second coil is used for the speaker-phone (hands-free) output for the factory cellular phone. It's worth noting this for those who might use the factory phone, and then replace their speakers! Also bizarre is that the wire to the left set of speakers is a thicker gauge than the wire for the right speakers. I just taped off the wires that fed the second voice coil.
To get at the speakers, you have to remove the door panels. Remove the two visable screws at the upper corners of the door panel. Remove the screw in the armrest, inside the grab-handle area. Now remove the oval-donut trim piece that this screw was holding inplace, by snapping the trim piece downward. This will expose two screws; remove them. The door panel is now removed by lifting it upwards, then out. You'll need to disconnect electrical cables and unhook the door latch cable.
The tweeter is held in place by a wire clip; to remove the clip, you have to first remove the trim piece that contains the tweeter assembly and door latch handle. Do this by removing the screw in the back of the door panel between the tweeter and the latch, then pressing the two locking tabs (located forward of the tweeter) rearward, allowing the trim piece to be pushed outward. Now remove the wire clip from the tweeter by pulling the forward end of the wire out of the mounting hole.
The midbass drivers are held in place by three screws in a non-standard way. If you want to replace these, you'll need to build your own bracket. The stock speakers are very deep for 4-inchers, enough that a normal set of 5.25" drivers might fit in the same depth; BUT, the grill cut-out is 4" in diameter, mounting would be more difficult, and it's actually doubtful that you'll be able to fit them not because of depth, but because of room around the door frame.
The 5 1/4's will fit!!!!!!!!!!