au xr6 over heating low speed

[tasauxr6vct]

Hey can't find any definite answers to this online but for the last 4 or so months my cars temperature has been hotter than usual the needle only spikes to the beginning of the 'normal section' when im not driving on a high way. But it used to stay very cold which results in my car going a lot quicker. It is fine on highways as cold air is keeping it cool i guess. Also the thermo fans are fine and are running at high speed when they should be.. you can really feel the loss of performance, it also get hot when u press it when it never used to. So apparently its i the normal section and mechanic says can safely go to half way BUT it used to always stay well within the first quarter on the temperature gauge so performance is greatly affected. Lucky its cold in tas now but when we had a hot dad few months back y car went to the red zone going up a hill and i lost heaps of fluid and burned most of my oil.. thermostat is all good and has appropriate amounts coolant , oil etc.. does this just leave the radiator or could it be related to something serious like ecu as other day no keys were in car and i opened glove box and radio came on and boot opened...

also when i brake the radio lights come on.. duno prob just bad earth or something i didnt do right when i reinstalled repaired pedal box etc

Cheers, i have so many more problems with the car that i will get to later...