First on my wish list would be some wheels which didn't look like stylised late 19th century wooden spoked cart wheels ( which most modern cars seem to have).Surely there is something which is more aerodynamic.
Next would be mirrors which didn't stick out like someone designed a body without thinking about how to see what lies behind.( how about cameras?)
Factory fitted crash and tamper cameras would also be of great use since supermarket damage accounts for most of my bodywork expenditure.
Wrap technology has moved with the times so renewable bodywork wraps which are printable would be a neat idea. People could change their car colour(s) design or finish within a day and also ensure that the dreaded tin worm is kept at bay.
How about something built into the engine which analyses and reports the ph, state of contamination and viscosity of the lubricant?
All wheel drive isn't really required to run much above 30mph for the majority of applications so it lends itself to the hybrid application very well; energy recovery is also easier to arrange from two, three or four inputs too. ( in fact, 4wd is only ever useful for the majority of us at less than walking pace in muddy fields or snowy car parks and drive ways, 4 wheel regenerative braking would in fact be used far more frequently than the extra drive traction)
TBH ,I havent looked at modern CT200s have they started to equip them with gas strut bonnet stays yet? My 2011 has an old fashioned prop which holds the bonnet open... Cuh!!! even the humble BMW Mini has gas struts holding its bonnet open!
Air conditioning systems could do with a built in system sanitising circuit... something which simply channels the 90 degC summer coolant through the cooling matrix in order to kill those bugs which make the air conditioning stink. This combined with better cooling matrix condensation drains which don't block up would save many owners the inconvenience of entrusting their pride and joy to the dealers air conditioning "specialist" ( sent by the manufacturers on a two week course if you're lucky instead of a four year college course which real air conditioning technicians have to attend).
Did you know that the highest speed land vehicles in the world have solid tyres? A flat road tyre may be eliminated by using better design of wheels and suspension along with solid tyres running on split rims. No goo, no pump, no space saver, no worries.
Thirty years ago, I drove a Toyota crown with a straight 6 2.6 litre engine. It handled like a camel on roller skates but when I dropped my friend off at the airport, I pushed a button from the drivers seat and the boot unlocked itself and opened in order to allow my passenger to access his bags. Very few cars seem to do this any more... why not?
I have a portable cooler which will run off a cigar lighter socket. Again the humble mini has a cigar lighter socket in the boot and yet the luxury Lexus CT200 doesnt.
Finally, there is very little storage space in my 2011 lexus CT200. except that if I need to I can keep half a gallon of drinks in a total of 4 drinks holders accessible to the occupants in the front seats. Not a single drinks storage space for back seat occupants or even an arm rest. Did this get fixed for later CTs or are we still waiting?
Those are just a few of my ideas. I hope this sows a few seeds and provokes a few thoughts.