Cheap RC Car

Work in progress
Goals :
- Make RC car
- Cheapest parts
- No screws (expect those from the electronics) or other materials
- Only with PLA and papercraft
- Easy to Customize
- Integration with my Pathdriver game (https://www.thingiverse.com/thing:1280442)
Electronics :
- Arduino nano (2$)
- servo motor SG90 (2$)
- Geared DC motor TT (1.5$)
- One small breadboard (1$)
Total of around 5.5$
Control with HX1838 (0.80$)
I want to share before it's finished if someone want to help me or have suggestions.