Im pretty terrible at building. and i need help fixing this ugly looking thing fast. If you have ever played the game blocks n props this is kinda same idea. The ramp is like a treadmill the launches cars and wtv. and in the center is supposedly supposed to be blocks and stuff like in jenga but thats but beside the point.
I think if you are looking for the same style as the photos you attached later in the message putting the darker wood as the block in the middle with some metal trims would work alright and match that asthetic.
Imo maybe you could add some warm spotlights around the edges shining into the middle to achieve the same warm lighting you have in the other builds.
I think the white fog effect on the parts that you have might be a bit too bright as well for the scene so maybe turn it more greyish/black to fit the vibe of the other builds as there isnt anything overly bright in those images.
As for the car ramp you could go for the simple metal with wood trim again and then build off there.