I want to buy an S4 Avant, probably a 98/99 model. I need to know what the likely running costs are (ie servicing, tyres etc) based on an annual mileage of between 20,000 - 30,000 miles. Any other advice/tips very welcome!! Thanks.

Hi DougS4, welcome to the forums.

Do you live in the States? The S4 wasn't released until 2000 here. It's hard to put a price on annual repairs/costs as it varies by driver and car. I would average it to be a bit higher than other cars and especially japenese models.

just take take of it and it should last a long time, ya the services will cost more the regular cars