No need for an equatorial mount for them. Just get an Argo Navis and encoders and your set. Nice and quiet too. No whir click buzzzzz.
Truss dobs will fit in a much smaller car than a similar sized solid tube dob (12" and up anyway). If you are only using it at home and it's relatively smooth ground to where you view from, put some wheels on the baby.
Astro_south has a 12.5 inch truss dob. Have a look at it
here or mhodsons 12.5" on an EQ6
here
And here's a size comparison of Astro_south's 12.5 and his car
here. Check this out as well
for another comparison . Apart from the struts it all fits into the base box and slides into the back of the care