Dear Sanjay,
You have asked a query on subject that is quite vast. Process or manuals are for handling operations whereas supplier development is a part of strategic procurement activity. Strategic procurement helps you in deciding direction of development.
You need to prepare Strategic Procurement Plan (SPP). Generally SPP lasts for 3-5 years. Part of SPP is Vendor Development Plan (VDP) which lasts for 2-3 years.
You have asked for VDP of auto manufacturing companies. Automobile companies have hundreds of vendors as assembling cars is a complex activity. VDP of automobile company is too big to be converted into process or manual.
Have you taken training on Strategic Procurement? If not, first you need to do that. I would not recommend you taking training directly on Vendor Management or Vendor Development without Strategic Procurement. I conduct training on Strategic Procurement. If you wish to know more about this training then you may click the following link:
https://docs.google.com/document/d/1...d.m0h4gvsfi169
Thanks,
Dinesh Divekar