Hello John, hope all goes well with you.
You might consider a clear 'clingfilm' type solution to your problem.
See Car Builder Solutions - 'StoneChip Protection Film'
you can download their catalogue from their website - see link below
See page 427 which also has tips on applying this firm
I believe that it is called Ventureshield and made by Scotchguard 3Ms

http://www.carbuildersolutions.com/uk/CatalogueRequest
I have not used it myself, nor know anyone that has.
I believe that their are other thicker alternatives on the market, which I believe offer better protection but are harder to apply.
Hope this may be some help - Chris

Thanks Chris, I will check it out.Cheers John