98 Honda CRV, Overheating randomly what is the cause?

Hi, I have a 1998 Honda CRV that tends to overheat randomly (after an hour or so of driving) and go back down to normal. I replaced the thermostat and the problem still persists. We also checked the water levels and it does not seem to loose any water. What could be the cause?

Honda crv97(What part is this)?

What is this tank it looks like a air tank i got into a accident and crashed on this side. Definitely not the washer fluid tank cuz its on the other side and this one has a fat tube like used to suk air were as if it were filed with liquid it would have a thin hose

Honda cr-v on a 52 plate (towing electrics )?

I own a honda cr-v on a 52 plate. Can anyone tell me does it have a hidden socket for a dedicated towing electrics loom and where is it hidden and where can I buy one from? Or can anyone tell me the order to wire a universal socket I. E what colour from socket goes to what colour on the car (right hand drive )