i got a couple of problems with my first car , ford escort 1.6 LX
first, sometimes , the RPM goes up to 2 and 3 without me pushing the accelerator , i'm not sure why...even when the car is warm..

second , i noticed that the car is very hungry for petrol, that might be the result of the above problem, but can anyone advise about the best economical speed on motorways..

it has done 48 000 miles, with no service history , any suggestion when should i change the cambelt?

the trunk doesn't open from the inside ( button doesn't work)
rear screen wiper sometimes it works , sometimes it doesn't

otherwise the car is very nice to drive
please guys give me your advices
cheers