[JmOz01]

If I wanted a vehicle that could serve as a (Very small) motor home, how would I do it.

I am looking for a bed, a bathroom, and a small fridge/food dispenser...

Also how would I go about doing the mods.... 

[Herr Brackhaus]

Any vehicle (presumably with the exception of open topped ones unless you like sleeping in the rain) can serve as a Lifestyle even without modifications.

A standard vehicle provides accommodations equivalent to Low lifestyle, by default, but amenities can be improved to middle, high, or luxury.
<znip>
A character can choose to live in their vehicle, but must still pay the full cost for the chosen lifestyle.

So, if you wanted to live in a very small motorhome, you could just buy a Ford Americar and call it a good'n. For 500¥ you could even upgrade from a Low lifestyle to a Middle one...

[Reaver]

While I don't have rigger 5 yet (away from any store that sells it, and I don't trust the mail system to deliver one where I am...)

There are a couple real world options that you could convert to SR5 if you do choose. (Remember, the vehicles listed are not ALL the vehicles out there!).

The first is a truck camper. Its basically a dwelling that fits into a 1/2 to 1 ton truck bed with no modifications.

They come with a bed, toilet, sink, stove/hotplate and mini fridge and limited seating. (I have used them lots on jobsites too remote for actual hotels) they cost between $8k to $12k new, with used ones as cheap as $1200....

Talk to your GM, he may allow it. (I would and do).

[Herr Brackhaus]

I'd totally allow what Reaver is talking about if you bought a Toyota Gopher for example. Something like a Bulldog Step-Van would also do in my opinion.

[JmOz01]

Are there stats for minivans

[Coyote]

I think that the GMC Armadillo is specifically intended for this, and off the top of my head, one of its listed rear options is actually some kind of camping or mobile home setup.