Andy tfsi

We've had our 2006 (06) Octavia VRS TFSi for a couple of weeks now and notice there seems to be a constant rumbling from the rear when cruising along, Don't notice it in town, it's just noticeable after about 30mph. It first sounded like very loud road noise from the tyres, it's hard to tell, we have directional Goodyear eagle F1. maybe it's just the tyres...not too sure Any help or past experiences of similar symptoms would be much appreciated...thanks

for me it's down to miles per tank. Managed 300 today on v-power before the fuel warning light came on. Filled with optimax to see what I get from that. Next it'll be v-power