2018 Audi Q5 SE 2.0 TDI quattro - aftermarket towbar and tyre road noise?

[rrollins]

Finally taken delivery of a 2018 Audi Q5 SE 2.0 TDI quattro s-tronic in Monsoon Grey with pano roof, hill hold assist and elec folding mirrors to keep under £40K as I hate paying tax :-) Very pleased with it.

1. Does anyone know if an aftermarket towbar is available?
2. Whilst I'm not used to driving a Q5 nor indeed a large SUV, should I expect a significant road noise (a whirring sound) from the 18 inch wheels especially at 40 mph and above and depending on the road surface?
3. How can I compare this to similar models? Take a test drive?
4. Does the sound insulation increase/improve through the model lines e.g. higher in S-Line?