Populate nested relation over two entities

Hi there, I’m currently using strapi v4.0.7 and I’m having a hard time querying deep relationships. I’m using Sqlite for the moment.
My model looks like this:
I have a user, which is the users-permissions user. This user can have 0…n cars listed in their account. For each car they can add one rating, but of course the car entity as such can have 0…n ratings.
At the moment I’m trying to query the rating of the user for one specific car. Say I have a Camry and I create a rating for it, and on my profile page I want to view the rating. How do I go on about this? So far I’ve got this:

const userWithRelated = await strapi.query('plugin::users-permissions.user')
      .findOne({
        populate: {
          car_models: {
            populate: {
              ratings: true
            }
          }
        }
      });

Which returns all ratings for the car not just the one of that specific user. Now on the rating entity I have defined a user field, which carries the value of the user, which should in theory allow me to filter the rating of that specific user out of all the ratings. Sadly though, in my populated ratings I get only the rating’s fields without the relational field of rating to user which would enable me to filter. How can I fix this?

To further clarify the relations:
User has a ratings (plural) fields to model relations to rating
Rating has a User field (singular) to model the relation to the user.

Any help would be appreciated.

Greetings, derelektrischemoench