I know door locks on these platform cars arn't the best but i only seem to have a problem when weathers warm,

When i press buttom on fob once it unlocks drivers door only as it should but sometimes when i unlock it it unlocks both drivers side doors front and rear,

Now i suspect it prob a faulty door lock, anybody changed one or know how much they are

Could be that the CCU is not very well. Get the car scanned with VCDS.