I don't believe they had that option back in 1976.
Unless it is the Luxury edition, the seats do not fold down.
If the Impala is the same as my 2001 Monte Carlo with a 3.8 L engine, the resivoir is on the pass. side way down low in back of engine compartment. You need a bright light to see it and it is very hard to get at!
09 chevy impala rpm jumps up and down
It should be right up front on the engine in back of the radiator down low towards the drivers side.
down uner the glove box
Down same tube that holds trans dipstick.
I have never seen any of the Impala rear seats that fold down other than the stationwagon
behind the alternator near the firewall about 3" down
if it is a 3800 series 2 or 3 engine, look at back of engine near passenger side firewall...it is set down low just rear of the belt
Connect the wiring harness on the back of your new radio. Slide the radio into the radio slot. Tighten down the radio retaining screws.
Depends on the year but 1994-1996 is behind the licence plate just pull it down an the cap is there.
Turn the wipers off, pull the wiper arm off, and replace it in the correct down position.