SOLVED: Djetset #300 - Prospect Four aircraft, designed to carry the BMC Mini and its passengers

[Djetset]

No, you haven't tuned into AeroPuzzles by mistake, this is AutoPuzzles, with a rather unusual one for my 300th mystery (only 1,200 more to go to follow Otto's amazing tally; well done Otto ).

There is a car connection here (otherwise I wouldn't have posted an aircraft puzzle!) so for a point, please tell me what this is, ideally including which car is connected to this plane.

A better photo will be added once this one has been solved.

[Djetset]

Get ready for take off Experts.

[guido66]

Does it share it's engine with a car?

[Djetset]

No.

[Djetset]

Pros, something for the weekend for you, as I fear this one may stay grounded for too long with the Experts.

[Arunas]

Is it Havilland?

[Djetset]

I'm no aviation expert, but a colleague of mine who is assures me that this aircraft was produced by at least two companies, but sadly de Havilland was not one of them.  This specific example though has a car connection.

[Arunas]

I have read that Franc Costin has worked/designed something for Havilland.

Is it British plane & car?

[Allan L]

I know some of you are working in a second language, but the names are de Havilland and Frank Costin please.
Both were English.
Frank Costin worked at de Havilland for a while, but at a pretty junior level.

The aeroplane looks as if it might be a preliminary study for the Richard Noble ARV Super2 (which became this)

[Djetset]

No, it's not an ARV Super 2.  However, bizzarely there is a very remote link with Frank Costin and the car that is connected to this aircraft!  The car and aircraft are both British.

[Djetset]

As I've not been actively involved with AutoPuzzles for a couple of months, to mark my more regular return I am feeling generous, so I will now award one point to anyone that can correctly name the car connected with this aircraft (and ideally how and why), plus another point for anyone that can identify the aircraft itself.

[jotage21]

This is an airplane with the Porsche-designed aero engine?

[Djetset]

No, not that.

[Allemano]

Is it a real plane or only a drawing? (In the René Magritte-sense it's not a real plane in both cases, but let's ignore that for a while.. )

[Djetset]

The illustration is just a drawing, but I am told by a reliable aviation source that at least one real aircraft was made.

[Djetset]

This flight has been delayed for too long, so it will be flying into the Black Hole very shortly.

[Allan L]

I feel I should know something about this, but my field of aviation is rather larger aeroplanes. It looks about right as a contemporary of the ARV I suggested 10 months ago. Is that date (mid 1980s) right or are we looking at something older but forward-looking?

[Djetset]

Much more forward-looking Allan, as this aircraft is from the early 1960s.

As a strong clue, the car associated with this aircraft was big news and gaining an increasing following in the early 1960s. 

[DynaMike]

Any relation to the Mini, then ?

[Djetset]

Perhaps that clue was rather too strong!  Yes, it is related to the Mini, so a point to you for identifying the right car.  Any ideas how it is related though?

[Djetset]

This one will finally be flying into the Black Hole as it's been waiting on the runway for far too long now, so any more ideas?

[Djetset]

Now coming into land at the Black Hole!

[Oguerrerob]

Any relation with Austin Aircraft?

[Djetset]

Not directly; no.

[Majeko]

Was the plane built by Auster/Beagle?