My sister in law recently bought a 54 reg Mercedes CLK 270CDi auto with 130k on it.
Over Christmas she came to stay with us for a few days which involved a motorway trip of some 250 miles. On her arrival she mentioned to me that the car was not returning particularly good mpg, about 45 compared to her previous MB (the same model) which returned an alleged 67 on a run.

I took a look under the bonnet for her and immediately noticed a fuel leak from somewhere near the pump. A bit more nosing around and I found there to be oil in the top of the header tank and the usual white creamy substance on the lid.

This is worrying as it could mean a crack somewhere within the engine as we all know.

As she has only owned the vehicle for a matter of three weeks am I correct in assuming the supplier is obliged to rectify these two issues?

To make matters worse, her husband has been shipped to Riyadh with his job recently so she is having to deal with this herself hence my, hopefully helpful, intervention.

She is not too happy about driving the vehicle the 100 or so miles back to the dealer so, would it be acceptable to expect the dealer to collect the vehicle from her house and furnish her with a temporary replacement whilst any repairs are completed?