here some code showing what I mean, see if you can bolt it into what you have.
sync on
sync rate 60
autocam off
position camera 0,0,0,-10
rem make boxes for wheels and position them
make object box 1,1.5,1,1
make object box 2,1.5,1,1
position object 1,-2,0,0
position object 2,2,0,0
rem make mesh to add a sphere to turn wheels with
make object sphere 3,1
make mesh from object 1,3
add limb 1,1,1
add limb 2,1,1
delete object 3
rem link them so that trhe main object is free ro rotate
link limb 1,0,1
link limb 2,0,1
do
rem turn left
if leftkey()=1
rotate limb 1,0,limb angle x(1,0),y#,limb angle z(1,0)
rotate limb 2,0,limb angle x(1,0),y#,limb angle z(1,0)
inc y#,1
endif
rem turn right
if rightkey()=1
rotate limb 1,0,limb angle x(1,0),y#,limb angle z(1,0)
rotate limb 2,0,limb angle x(1,0),y#,limb angle z(1,0)
dec y#,1
endif
rem free wheel rotation
rotate limb 1,0,x#,limb angle y(1,0),limb angle z(1,0)
rotate limb 2,0,x#,limb angle y(2,0),limb angle z(2,0)
inc x#,.5
sync
loop
Dark Physics makes any hot drink go cold.