Hint: Newer work is found at Book - Solar Car

Solar Challenge 2 time winner - 2009, 20011 - Tokai Challenger - 62 mph average for Solar Challenge Winner- 1.8 kW PV array, 30% efficient, 352 lbs, 16'7" by 5'5" - [1]. 90 square feet of area.
Increase that to 24 feet long x 8 feet wide (192 square feet) (2 kw) - like a trailer - to double the area. Use non-exotic solar panels to keep cost reasonable with solar. Add 20 kg of lithium ion batteries for 4 kWhr [2] of power, and a small backup engine (2kW) - for one hour of up to
PV panels - 1650x990 cm is 17.5 sf. See slide 12 of Open_Source_PV_System#Initial
11 of these panels fit on the 192 sf area. Each is 285 watts for 3100 W total. Under normal conditions - power should be 1.5kW. If we double that with an internal combustion engine for 3-4kW - we are pretty good to go for sppeed.
The main challenge in using Open_Source_PV_System#Initial PV panels is that they weigh 19kG each - so 209 kg total. That is 460lb already. Small engine would be 5 lb, and batteries at 44 lb - with frame + drive at 240 more lbs. That makes for a 750 lb vehicle.
Can we get frame to within 240 lb? Yes, with carbon fiber composites. But aluminum would be tough. Suggestion: 3D printed frame as skeleton for carbon fiber layup.
Frames - carbon fiber is 5x less weight than steel frame, and 2x less than aluminum. [3]

OSE Implementation

General

For a practical 200mpg equivalent solar car for OSE, we can think of a box truck with a roof to carry 20 solar panels, 2 2kW silent generators for auxiliary power, and open source electric motors. It would also have a 1Kw battery pack from r rapid acceleration,such as 20kW boost for 3 minutes.
Solar power would be on the 24x8 foot roof - 200 SF for 3kW of power. There would be telescoping extensions to double power to 6kW for cruising speed.
It could potentially telescope to 9kW total when standing for rapid charge, but this may not make much sense if small size and small battery pack are used. $1k gets us up to 3.3kW of battery storage.
This would be quite the vehicle with battery, solar, and wood gas.
Carbon neutral, unlimited range.
Practical
Curb weight of 1000lb with plastic fiber composites that are 3D printed.
120lb generator for 3 running kW
3kW panels (30 panels) weigh 96 lb.
Structure - 500 lb
Motors - 100 lb for 2x10kW running power
Batteries - 15 kg for 3kW
9 running kW - 40kW peak for 30 seconds
3D printed airless tires

Vehicle lengths in the USA are typically 65' [4]
Vehicle telescopes, so it has a a normal length of 20' (size of a van) to 30'.
This is 8x65=520 square feet, or 48 sq m.
Take a Sunelec panel - [5] - Heliene 300 - 65.5 × 39.4 in - for 300w. [6]. 2581 sq in or 1.67 sq m. This is 180W/sq m.
There are 29 solar panels in this area.
48 * 180= 8.6 kW
Thus, a large trailer would have a total energy capture of 8.6 kW (11.5 hp)
This is plenty for driving on flat land.
Typical rolling resistance is 1.5 hp for 1000 lb of vehicle. [7]. We can allow for a 2000 lb vehicle to make this easy.
Each panel is 50 lb [8]. 29 panels make it 1450 lb - leaving only 550 lb for everything else - which is difficult. There is a strong case for flexible panels that are 82% lighter [9]. In which case the structural engineering is easily doable without extreme performance design.
Flexible panels are not as durable.
Case exists for a heavier vehicle with stiff panels.
Say 3000 lb weight - but that gets into pushing too much mass around. Doable. With 11.5 hp available, 4.5 goes to resistance, and 7 hp to drive (5 kw).
There would be a 20kW auxiliary battery pack for added power.
All together, this makes for an interesting city vehicle that can also be designed for highways.
A telescoping vehicle is one route to try, and it is definitely a viable idea.