Hi all. My Antara SE Nav is 18 months old, and now done 18K miles. Really superb car, no problems until now (DPF gripes aside!!). Anyway, I noticed road noise, droning sound, at 20mph increasing in volume, worst at about 50mph. Was OK last Wednesday, but seemed to start happening on Thursday. Took the car into Kwik fit and had all the tyres checked - 30% remaining on front and 60% remaining on the rear - all original Hankook tyres. Kwik Fit technician suspected "castelation" or "blocking" due to issues with suspension. Not convinced by this I asked him to check the balancing on the rear tyres and swap the front and rear tyres to even the wear. He said this wouldnt make a difference to the road noise - he was right! So, the car is with local Vauxhall dealer now for investigation. My theory is that the due to the front tyres being worn more than the rear ones, then effectively this means that the front ones are going faster than the rear ones - if that is the case, could it be enough to confuse the intelligent 4x4 and engage 4x4 permanently. As there is no indicator for 4 wheel drive I cant tell. It could be a wheel bearing - or could be some issue with the Hankooks, but they look OK to me and why would they get noisy overnight? I thought the tyres were doing amazing, and wasnt expecting to fork out for new ones for some time. If they have failed due to fault or design issue with the vehicle, should I get new ones under the warranty? Anyone had anything similar?