Your right Sobek, i think it would take about 10 bottles of Raptor to do a full car with the recommended 2 coats. A bit out of budget...
These bed liner products can be rolled on. So if you were doing your roof and bonnet, i think a bed liner product would look pretty cool.
Good story on your XJ. Its part of the family!
These guys use bed liner type products on panels. Some nice examples here. You could do a few bits at a time within budget.
http://davisautosports.com/xj_build_gray_stage3_kevlar
Cheers,