FWIW, I'm getting close to having a beta version of the UPS shipping module that makes use of the now-current RESTful API using OAuth authentication. Once the beta is published, I'll be asking for help in the validation of its interface as I don't have access to any non-US sites that make use of UPS shipping nor do I have access to a site that uses negotiated rates.

The plugin's GitHub repository is https://github.com/lat9/upsoauth and instructions as to how to receive the OAuth Client ID and Client Secret can be found here: https://github.com/lat9/upsoauth/wik...-Client-Secret