Building backlinks on a niche directory site

Hi, just looking for some tips on some good ways to build some backlinks on a niche directory site. Ive built a new carboot directory site (not sure i can post links, so let me know if it would help to see the site).

But essentially carboot sales are quite niche i.e there are not many blogs to guest post on, nor are there many forums, just wondering what ideas you have for building backlinks on sites like these

I started working on directory and i was thinking of doing lists of websites where i would list my site first. Like top 30 local business in France