Coskun Sunali posted an amazing article how you can set up VirtualPathProviders to run when using Precompiled sites.

Do you know that even MS do not use VPP in precompiled sites? Check this out.

This is just an example what you can achieve with Reflector and a lot of patience.

(The support for VPP is explicitly disabled in precompiled sites by Microsoft. We do not know the reasons why they did it, so please you this fix with careful testing :).)

Good work Josh!