Hi Andy, sorry for the delayed reply, we've been flat out for weeks now, and we are struggling to find time to get on the boards. The HD wax is getting a lot of positive reviews, but it's not something we've used or will try, as we're not interested in stocking Autoglym products - we favour little known brands with a more upmarket boutique feel.

For polishing the cars mentioned above, please note that they will have very different paint types - the GTR will be soft, while the RS will be hard. Thus, a different appraoch will be needed on each. See here...

GTR - By Hand: http://www.polishedbliss.co.uk/acata...e-faq.html#3.5

GTR - By DA machine: http://www.polishedbliss.co.uk/acata...e-faq.html#3.8

RS - By hand: http://www.polishedbliss.co.uk/acata...e-faq.html#3.7

RS - By DA machine: http://www.polishedbliss.co.uk/acata...-faq.html#3.10

Also, the bird crap mark you describe sounds like sub-surface etching, caused by the uric acid in the crap eating into the surface of the paint (this would explain why the clay didn't touch it - clay removes bonded dirt and grime, but does not address sub-surface defects etched into the paint). The above polishing methods should help to correct the mark, but note that sometimes etching can be so deep that no amount of polishing can safely remove it.

When it comes to protecting both cars, I would suggest carefully reviewing these links...

GTR - http://www.polishedbliss.co.uk/acata...e-faq.html#4.2

RS - http://www.polishedbliss.co.uk/acata...e-faq.html#4.4

If you want to save some cash, then the Werkstat Acrylic system would look ace on both; see some example images on a grey GTR here...

http://www.polishedbliss.co.uk/acatalog/may.html

I hope that helps!