Tools and Techniques for Analyzing German Automotive Discussion Forum Posts
You could go with different approaches:

Lemme point few,


You could just extract the keywords or tokenize out of the query using libraries like spacy or nltk, both support german languages. Then go for like page ranking approach, based on query optimization: Uber.
You could go for Attention based seq2seq model, where you feed the inputs as questions and the answers as output. More like how you train chatbots and language translation models. This is popularly known as Neural Machine translation. Tensorflow has an open source implementation. nmt


The second one is feasible because it has tonnes of examples out there. But try to use spacy and nltk for tokenizing according to German language and also try to use German word embeddings: example, which contains pre-trained weights on huge corpora representing each German word.

Hope this helps.