How to install a Power Inverter?

Ok. here is the problem i am having.

my power inverter likes to stay on after i shut the car off. It is an 800 watt/1600 watt peak power inverter with a Digital L.E.D. display on it. While the car is off it is still drawing 2.95 amps. which i found rediculous. One of my previous teachers told me to put a relay (SPDT) on it.

he told me to:

connect pins 85 and 30 to the remote wire from my amps so that it will shut the power inverter down when the radio is off. (thats a given)

ground pin 86.

and then on 87 have the wire come off of the relay and then to the amps and the power inverter. The wire that i use for the remote turn-on is a 16 gauge. Well what I having problems deciding is will the 16 guage wire be able to turn on the power inverter. Or will it fry the wire.  The only reason why i say this is because it has an 8 guage wire on it now thats fused.

Right now the power inverter has to screw-type pins on it. I have it grounded on my ground distrobution block and the power wire is an 8-gauge wire (as is the ground wire). Is there a way that i can add another relay or something that i can fuse after the +Boost Relay (which i stated above) to make the wire go from a 16 guage wire to an 8 guage wire.

Please someone help me with this ASAP!.

hmm.. i probably didnt wire my up right but it works... it came with either a 12volt cigeratte lighter cord or two cords for hooking onto a battary.. well i took the cords with the clamps on them.. cut off the clamps.. tore my console apart in my '03 impala. spliced into my cigeratte lighter wires.. took out my drivers seat.. did some testing to make sure it had room to fit and where to be so i could move the sit forward and back w/o movin the inverter. i also put a switch underneath the wheel since the cigeratte lighters always have power.. even if lights or doors are on.. the car automatically shuts everything but the lighters off in 20mins.. (did some testing, lol) one thing i did notice today was.. i was sitting in my car playin ps2 and well i decided to start my car up.. after it started. it must have had some voltage spikes or something cuz the ps2 would turn on or anything.. shut the car off... came back like 10mins later.. turned the car on.. the inverter on.. and the ps2 was working.. oh well..

if anyone has any comments on how i wired it up.. give um to me.. anyone have any info about the ps2 getting spiked hit me up..