1. Load your farm and Charles 

2. Open the market, select the vehicle you want to buy, but do not place it yet. Let it hang. 

3. Enable breakpoints 

4. Place the vehicle on the farm.(Charles will now pop up)

5. In Charles, click the Edit Request tab at the top and then the AMF tab on the bottom. Expand the params + and then the next + and find, - m_equipmentPartsCount. Then change the number beside it.

The number you change it to depends on whether it's the combine or one of the other vehicles. For the combine, u will change it to 96, for the others it will be 32.  

6. Execute 2 times and disable breakpoints.  

7. Refresh your farm. that's all..