Hi can anybody tell if a audi cabriolet 2.8 v6 1999 can use E10 petrol as the government web site Is useless thanks Adie Shu

 

I'd say that a 1999 model is less likely to be compatible. 

The fact that the gov website only covers Audis back until 2001 also suggests you have a problem. 

Everything after 2011 is good but even if you allow for forward planning by manufacturers, 2000 is at least 2 iterations before 2011. 

You should probably ask your local Audi dealer.