Best place for a 4-channel amp in an access cab?

I recently installed new speakers in my tacoma: alpine 6x9 Type-S SPS-609 85 Watt 3-way coaxials in the fronts and infinity reference 6032si 6.5 in the rears. I'm guessing they really need to be amped because they kinda sound like crap right now and these speakers are supposed to be decent. They are being powered off of an alpine head unit. Space is tight in my access cab though. Where's the best place to mount a 4-channel amp? Any amp recommendations? I don't have that much cash left to spend on my truck after just installing a new grill and side steps. Thanks

 

Under the seats. Driver or passenger side. Get a low foot print amp. I have a 02 and I tucked a JL Audio HD600/4 under my driver side. Two channels running my front and rear components while the last two channels going to run a single 12:

 

under drivers seat


that the only place


i have an amp under the drivers seat and pass. seat
but the drivers seat has more room than the pass seat.

 

I put my JL 300/4 under the driver's seat. Pretty much any amp to power those speakers will fit great under the seat.

One thing to think about is if you ever do a water crossing, you could risk getting the amp wet if you get water in the cab.

 

As above, under either seat. With the passenger you have to flip that support bar upside down. If you do that, the passenger seat actually has more room than the driver.

I've got a JL HD 900/5 under the passenger seat and a HD 600/4 under the driver's.