My cousin has a 91 camry and I was wondering if anyone knew offhand where to get installation instructions for an amp and a base box?

There are none. You have to run the wires yourself. Run a positive wire from battery through firewall (near driver side foot rest). You will need carbide tip on the drill for hole. Place rubber garmet in it so it doesn't poke a hole in your wire. If there is plastic trim on floor near driver door, disconect it and run it to the back of the trunk. This involves lifting up the plastic trim and carpet. Other wise you could do it ghetto and let it be exposed. Once you get the wire to the trunk, find a ground and use no more than 3' wire for ground. Use at least 8 guage for the wiring and maybe bigger deppending on wattage of amp. Once you get that figured out. Run RCA cables from your cd player on the opposite side of the car along the passenger doors under plastic and carpet. Reason for this so it doesn't interfere with the power on the other side. For guidance and help try sounddomain.com Also poweracoustik.com for tips