[euromodder]

Originally Posted by NeilBlanchard

The sides are about 13 degrees but to increase this, the rear track would have to be narrowed more.

Then I'd say it's better not to reduce width at the rear, as a narrower track will also lead to a less stable vehicle.

The hatch would still have to be there to use the storage area -- if it was shortened by half it's length, and the upper portion of the rear doors was joined to it?

While keeping the height, the hatch could be reduced to just (a) vertical rear door(s), fitting within/onto an efficient ringlike structure (C/D-pillar) - much like it is on a near-vertical hatchback or station-wagon design.

Reducing rear height would likely require a roof cut-out to get proper access to the luggage area.
As this also reduces luggage space and overall volume - practical things really worth having - it's probably better to keep the current size of the rear end and put the available volume to good use.

The one side door would be roughly the same size as the reduced hatch, though it would add more weight;

It'd take a structural engineer to calculate the weight impact of both options on your design, but I really don't think you can get away with the (full sized) roof hatch very lightly.

because the change in the hatch is just the length of the 2 sides, and the side door has at least 2X that perimeter length.

Adding multiple small holes to a design doesn't have the impact of adding one larger hole of equal area.

Even going with one side door would still double the access options of the design.

The two side tubes would have to continue through the door and it has two hinges and at least two latches.

It'd still require structural stiffening - any opening will require that - but efficient car door design is nothing out of the ordinary, as there's a lot of expertise in that area.

Through the entire car-era, side-opening doors are very much a constant feature. None of the alternatives so far have stood the test of time.
Last rumour I heard about Loremo, they were considering reverting to conventional doors.

I can feel it's a pet-feature on your design, but IMHO it introduces too many undesireable effects to be really viable
- single entry/exit point for all passengers and any cargo
- seating arrangement (bus-like, i.e. none too cosy)
- severely limited headroom for aft passenger
- large % of wasted floor area by requiring a free aisle all through the vehicle
- voluminous loads would block entry and access completely (no van-variant would be possible)
- huge single-opening for a small design

I know of no vehicles with only a rear-entry option.
This in itself is not a good argument, but it should get the alarm bells ringing as to why it hasn't been done (more often) before ...

The seating in the VLC's is low to the floor of the car, and the sides are protected by the tubes of the chassis; and you have to step over them and sit down in beside them. Getting in and out is not equivalent to a conventional car.

Sounds a lot like a Lotus Elise.

Such design options also severely limit a design's usefullness to many people - the fast growing crowd of elderly people who aren't as nimble as a youngster.

That said, CarBEN's rear-entry design could be easily adapted to transport wheelchair users - if the driver can still get in after the wheelchair is rolled in, that is.

Personally, I find upright seating much more comfortable, and riding a little higher than a typical car helps the visibility.

A lot of people feel that way, and it's a design option used in just about every European MPV design (Renault Espace, Scenic, Modus, Opel/Vauxhall Meriva, ...) as it allows the designs to be shorter while still giving plenty of leg room.

Sliding doors are hard to do and heavier than swing doors.

Agreed, but they're also highly practical in confined spaces.

If I end up doing solid/non-inflatable tires

Something like Michelin's Twheel ?

And guys -- this is a prototype! I think it is well worth trying this out, and seeing how it works.

Sure, but it's very useful to think out the practical side of a design before prototyping it.
It's easier to change the design than it is to change the prototype

I'll bet getting in and out of the CarBEN is faster and easier than putting on a motorcycle helmet and crash suit and gloves?

It sure would be.