Non PT Car Audio question for an Audio guru

[LowBuckX]

I bought a 99 Buick Centry today and it has the Premium sound package. I dont want to cut it up to put a din head unit in but I do want to put my subs in it.
What is the best method for this? I used to use line level converters but this was a long time ago. Is there a better way to do it in these newer cars? If not who makes a good line level converter nowadays? Scoche used to be what I would use because you can get them anywhere.
Thanks

[LowBuckX]

I just had a thought.. How the heck would I turn the Amp on? What would power the remote turn on?

[SHANE 73Z]

I take you are going to power the subs, by the power on question. Some amps have the low level line input built in to the amp, that would negate the line converter.

I have also heard of using the circuit for a power antenna to trigger the on lead for the amp. If teh car was available with a power antenna, there should be a pin out on the head (even if not so equipped with p. antenna) to use.

Shane

[68BNUT]

A 99 will definetly have a switched radio power lead coming off the back. My 99 pickem up did.

[HILROD]

I have done this exact thing several times. First you can use the power antenae feed to power up the amp. I use a relay. Next you can get a the small converter to change to a pre-out like you talked about. It looks stock but works great. Also a great theft deterent. FRANK

[dannyho]

theres no reason to run a relay for the power side of the amp. the amp has a relay built into it, hence the need for a remote wire, which is essentially the low amperage relay input. if you put a relay in it you will just be makign a big opening for interference like the same thing a bad ground would do. the amp will cut the power on it's own. yea the power antenna lead will work, but make sure that its still got power when you're listening to tape/cd too, some cars the antenna goes down when you switch from radio to cd. your best bet would be to find an amp that has high level input and split the signal from one of you rear speakers, pretty easy to do. if you end up getting an amp that doesnt have high level inputs, a line output converter is 20 bucks at circuit city. on that remote wire, all you need is a switched 12v source, and it doesnt use enough current to do anythign to your electrical system, so i'd say go in with a test light and find any wire that'll work. if you have to run one to the fuse block, you're going to have to run a power wire from the battery anyway.
I just noticed that hilrod is also saying not to run a separate power wire from the battery, i think. I'm unsure because this is incredibly wrong to do. Not only can the fuse not take any decent amount of power, what is it? 15 amps, which at 12v is for a 180 watt amp, but more importantly is the size of the wire. if your wire is too small the resistance of the wire shoots up and the current has to increase to compensate, usually resulting in a fire. here's a page that lets you know which size wire you need.
http://www.carstereo.com/help/amp_instal.cfm
now remember power=volt*amps, and that would be RMS power, not peak, peak power does not blow fuses, ask an electrical engineer

[LowBuckX]

Ive always ran a lead from the batt to the amp. Im going to recycle the install kit from my current car to the new one so it is proven to work.

[HILROD]

The last car I did this in 2003 GM wouldn't power up the amp, so I had to use a relay for the trigger wire. FRANK EDIT, You need to run a seperate hot lead for any sizeable amp.