I can see your problem Paul. The c/visions ads do make it very hard to see out and it does make it very dark inside the bus - so the lights are needed even during the day.I am not a frequent traveller on Citybuses but I am a big user of Ulsterbus. Ulsterbus only have a few all over c/visions. Buses that I have been on with c/vision are the following
1118 LXI 1118 NEWTOWNABBEY - AD FOR GUINESS
1260 OXI 1260 V02 - AD FOR N.IRELAND FIRE SERVICE SMOKE ALARMS
and
1322 RXI 3322 NB - AD FOR NEW DEAL EMPLOYMENT.
1260 is very hard to see out of because it carries quite a dark advertisement but 1118 and 1322 are not to bad as they are lightly coloured.