Terry Casey wrote:
Incidentally, I often notice, when travelling on vintage buses, that the
BS certification on ALL windows is circled in yellow chinagraph pencil.
I assume this check is part of the MOT.

The BS certification on PCVs is checked as part of the test, the
chinagraph circle is to draw the examiner's attention to it, as on older
vehicles,the mark is often faded and hard to find.

It may also be a requirement for Class 5 vehicles, but I don't deal with
those, so couldn't comment with any authority.

Note that many vehicles I travel on are privately owned and are NOT
licenced PCVs. (A PCV is subject to a much stricter MOT.)

If you are going down the polycarbonate route, I would suggest you check
this out.

Have you thought of having a word with your MOT testing station about
this?

Always a good idea. VOSA have a helpline and helpful e-mail contacts and
can often advise you without seeing the vehicle or having details which
will identify it or you:-

http://www.dft.gov.uk/vosa/contactus/contactus.htm

--
Tciao for Now!

John.