I have checked a bunch of sites and read up on the forums, but there are many different sizes stated.

I have a 1999.5 Audi A4 1.8T. It has the NON-BOSE, Concert audio system.

I THINK the fronts are 4" components, and the rears are 6.5" full range, but I wanted to double check before going out and buying speakers. Can I fit 5.25" up front building a plate?

Also, are there any amps in this system? It certainly doesn't sound like it!

Thanks,
-Brian

P.S. - I just bought this car yesterday and love it so far!

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2007 Audi A4 Quattro 2.0T S-Line 6-spd
- Dolphin Gray
- Convenience Package
- Heated Seats

1999.5 Audi A4 Quattro 1.8T - SOLD
2001 Ford Mustang GT Convertible Supercharged - SOLD

I think there actually is a small amp powering the 6.5"'s in the rear. As far as the 5.25"'s go, I'm not sure. I've got the exact same problem. I recently tried to have a 5.25" Boston Acoustics component set put in my '01 and they told me they were too deep and that the windows would hit them when put down. The people who were installing them told me that the size of the factory speakers are actually around 4.5".

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~Kolby

Factory fronts are 4", rears are 6.5". You can fit 5.25" in the front. You'll probably have to fab a front bracket yourself, but it can be done. I have Polk 5.25" components in my front doors.

The rear non-bosespeakers do have a small amp on the driver's side. If you go aftermarket speakers, your best bet is to get anamp to run both the front and rear speakers, and re-wire them with some thicker guage speaker wire. A small 8" or 10" sub probably wouldn't hurt; don't know how much you're looking to upgrade though.

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MCMXCIX Casa 2.8qt
SpeedTuning Chip, Tip-Chip, Magnaflow Exhaust, Koni Coilovers, 18" BBS LM Reps, K&N 57i

you can buy spacers allready made, that allow to fit around 5 inchers in the front, also pay to get some sticky sound deadener to seal aroundthe speaker and deaden the door a bit, (my door was pretty solid braced tho) I just fit today a pair of 5" Peerless definition series components in mine, the depth was fine, but I had to cut a little bit of metal outof the doors to fit.

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98 Audi A4 1.8T quattro, manual, APR/Oettinger chip, RS4 cosmetics, lowered, Santorin Blue Mica.

Where can I buy these spacers? I'm thinking about putting in a 5.25" Infinity Reference component set up front and 6.5" CDT AUDIO MID-BASS drivers on the rear deck.

Thanks!

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'04 Honda S2K 6spd
'99 Audi A4 Quattro 2.8 5spd
'97 Honda Civic EX w/'00 Integra Type R engine (sold)