i got lots of problems!

hey any help on these problems will be appreciated.

1. temp gauge stays up around 260 degrees & i've changed thermostat, flushed radiator, everything i can think of. idk wat else to do.

2. my a/c & heater don't work. they worked for about 5-6 months then just stopped. the a/c doesn't need to be recharged and as far as the heater i don't know.

3. my trunk constantly leaks the rubber seal seems to be fine, but idk if the trunk lid is unaligned or wat.

but all these problems and more make me nervous all put in more problems as they come up.

1. does the car run ok? any check engine lights? it might be an electrical problem. i was on my way to work in my old truck once and the gauge said about 270, so i had the heat on and everything, and then i hit a bump and it leveled out and read normal.

2. once again, possibly electrical. is there air coming out of the vents at all? if not, check connections under the hood and behind the dash. also, the vents could be clogged somewhere.

3. i'm assuming you have the spoiler, and judging by the age of the car, it could be just seals/gaskets around the lid and the spoiler. maybe try putting towels behind the seals, closing the trunk, and spraying a hose around the back of the car and seeing which towels are wet and where. has it been in any accidents that needed repair or anything like that you know about?

these are pretty vague answers, i know. if you post a little bit more about the motor (i.e. 3.1L or 3.4L) and the shape the car is in, hopefully somebody can give you something more concrete. but checking connections and looking for clogged vents won't cost money

oh i know lots about the engine/car had it for years no wrecks, its a sedan (so no spoiler), 3100 v6, its in great shape not even 150k miles.

1. the only problem when it runs is once in awhile it loses power around 55mph but that seems random

2. whenever i turn on the heat or a/c its like the vent is on it blows air through all vents easily with no problems

3. only problem with rear of car is a few cracks in bumper but thats from age. i know its from age cuz i do bodywork, i suck at mechanical things but i can make it look pretty

still seems electrical to me. if it reads 260 and it's not blowing up then there's something wrong with the gauge or you have the best motor ever built. randomly stuttering at 55 could be anything really, most likely just dirt buildup unless it's really pronounced. in which it could be an 02 sensor. but that wouldn't have anything to do with a thermostat or ac/heat. your ac could be a bad compressor, check to see if the hoses are hard and i've heard that means the compressor or the refridgerant needs attention. i wish i could help more, but i haven't done much of this odd maintenance either

blown head gasket exhaust is gettin in the coolant

Any codes for a coolant temp sensor?