hi there have been the proud owner of a wr1 for the past 14 years no real problems, knocking rear shock absorbers is one its a design fault usally nothing wrong with them, alot of people put coil overs on to stop it,as long as you have a good service history and it has not been abused you should be ok,my advice is dont mod it and these cars will go up in price in the future ,look how much you will pay now for a P1 NOW!!! also check the rear spoiler as rust forms undeneath common fault in all sti models.