I have an 05 S-Type 4.2. I just ordered the K&N Filter kit from Jaguar XP. I drew a line through N2O. Also, when I bought my car there was a performance suspension option that was available if you built your own (I took a car from showroom stock). Can the performance of the suspension be increased at a reasonable cost as an after-market solution? Also - looked everywhere - but I cannot for the life of me find navigation DVD's. All I have is the region that I bought the car in. Any thoughts from you folks on increasing performance and handling?