What is the fine-grained topic of the following text: It has been very difficult to manage all about the assembly of the new premium hatchback of the Opel company, as the German company has developed a model for an extensive program of personalization: the choice of the potential buyers are 61,000 exterior design options and 82,000 interior design possibilities. Only return the topic.
Managing the assembly of the new premium hatchback by Opel Company with extensive personalization options.