Great question — answering as the UphillTech team:
Start by making those backlinks nofollow in your snippets and tell your dealers to make them nofollow too. Your way of creating backlinks is now considered illegitimate. You will not recover the rankings your used to have through them, unfortunately.
Full answer by Jérôme Verstrynge: https://webmasters.stackexchange.com/a/67192 (CC BY-SA 3.0).
Need it done for your business? UphillTech.