Subaru Legacy 2.0 GL AWD Estate

Before I go any further, my model is the 99 LX Classic, a basic Legacy estate with Air con and Alloy wheels. It's still AWD and a 2.0 litre so it's probably basically the same. When I bought it, it was 18 mths old with 25,000 miles on it, it now has 51,000 and still going strong. It has a high/low gear ratio which I frequently pop in to low in traffic jams or for hill starts especially when towing my caravan. I have succesfully towed it (at 1000Kg) up the hills on Exmoor in low range, and in high I was forced to overtake a slow driver and lorry up a hill on the M4 south of Bristol. It is quite proficient at towing at the legal speeds ...