are they part of the sodo figure line?

It is part of the Yudo figure line-up. I guess it is just their way of drawing the line between rider and sentai.

So the official Bandai site says there will be two variants when selling the VS Changer. You can either get the Patranger set which includes the Trigger Machine 1, or the Lupinranger set which includes the Red Dial Fighter. The other VS Vehicles are each sold seperately.

source: http://sentai.b-boys.jp/new/products/

Are the VS Vehicles just for the Changer or are they also used for the mecha later on
Just wondering if I need to preorder all these vehicles

They look like baby toys to be honest.

Whatever, let's just see if the show's any good.

I dunno, I think these look kinda cool and I rally like the look of the Lupinrangers. Can see myself spending a lot of money during this series' run!

Y no Goodstriker yet?

Not as much as Toqger.