This list is incomplete, you can help by expanding it.
The Toyota CS&S is a four-wheel drive, mid-engine sports car concept made by Toyota and displayed in 2003. It utilizes a hybrid system combining electric motors to drive the front wheels, and a combination of a gasoline engine and electric motors powering the rear. It is the first Toyota vehicle to have the feature Toyota Space Touch.
The Alessandro Volta is a concept car developed in the collaboration of the Japanese manufacturer Toyota and the Italian design company Italdesign Giugiaro.   The concept vehicle named after Alessandro Volta, the Italian physicist who invented the battery (and the namesake of the volt unit of measurement), was officially unveiled at the 2004 Geneva Motor Show and it is a study of a hybrid electric sports car.
The concept never materialized as a production car due to high costs involved.
It features a four wheel drive hybrid electric powertrain of the Lexus RX 400h which combines a 3.3 L V6 gasoline engine with two electric motors. The gasoline engine is fitted behind the rear axle and there are additional two electrically powered engines, one on each axle. The combination develops a maximum output of 300 kW (408 bhp), which enables the car to accelerate from 0 to 100 km/h (0 to 62 mph) in 4.03 seconds and reach the top speed of 250 km/h (155 mph). It uses drive-by-wire controls.
|Body style(s)||4-door sedan|
|Engine(s)||Supercharged 3.0 L 1MZ-FE V6|
|Designer||Toyota Style Australia|
The Camry TS-01 is a concept car based on the Camry and was unveiled at the 2005 Melbourne International Motor Show in Australia. The aim of the Camry TS-01 was to showcase the skill of Toyota Australia designers and engineers.
Its major features are the stylist changes and the supercharged 1MZ-FE engine.
The Toyota 1/X (pronounced one-Xth) is a concept car built by Toyota and first shown at the 2007 Tokyo Auto Show. It is a gas/electric hybrid vehicle utilizing plug-in technology. The car weighs only 926 pounds (420 kg) but has as much interior room as the Toyota Prius.  The car's frame is mainly carbon-fiber reinforced plastic, which allows it to be light weight yet strong. The engine is 500 cc and sits under the rear two of four seats, driving the rear wheels. 
Toyota envisions the car to be made of seaweed in the future. 
|Body style(s)||2+2 coupe|
|Engine(s)||3.5L V6 hybrid electric|
|Wheelbase||104.33 in (2650 mm)|
|Length||170.27 in (4325 mm)|
|Width||73.23 in (1860 mm)|
|Height||50.79 in (1290 mm)|
The Toyota FT-HS is a hybrid sports car concept introduced at the 2007 North American International Auto Show. Calty Design Research designed the concept and suggests that it could fill the place of the Toyota Supra. FT-HS stands for Future Toyota Hybrid Sport.
The A-BAT is a concept truck revealed on 27 December, 2007 and manufactured by Toyota.   The A-BAT is the first Toyota to have a mid-gate allowing cargo longer than the standard four-foot bed to extend into the cab (like a Chevrolet Avalanche or Honda Ridgeline). Power for the A-BAT comes from Toyota's Hybrid Synergy Drive mated to a four-cylinder engine. The A-BAT officially debuted at the 2008 North American International Auto Show in Detroit.
On 22 September 2008, the website PickupTrucks.com indicated that Toyota had confirmed that some form of the Toyota A-BAT would see production, barring unforeseen production costs. The article also stated that Toyota had cancelled production of a Tundra diesel truck. Although Toyota later denied official confirmation of the Tundra's cancellation, no mention was made denying the statement regarding the A-BAT. Sources say that a production version of the concept will likely have a four-cylinder engine as an option, as well as a four-cylinder hybrid engine.
|Electric range||80 km (50 mi)|
The Toyota FT-EV is a small, battery electric, concept vehicle built by Toyota as a modified Toyota iQ and demonstrated at the January 2009 North American International Auto Show. It is claimed to have a range of 50 miles (80 km) per charge. Two of the iQ's seats were removed to make room for the battery packs. Toyota plans to start selling the FT-EV in 2012.
|Electric range||90 km (56 mi)|
The Toyota FT-EV II is a small, battery electric, concept vehicle built by Toyota as a modified Toyota iQ and first shown at the October 2009 Tokyo Motor Show. It differs from the FT-EV by seating four people, by having more parts of the body transparent and electrically operated sliding doors. A pair of linked joysticks (each joystick duplicating the other) control acceleration, braking and steering using drive-by-wire. The top speed is over 100 km/h (62 mph) and the range is 90 km (56 mi).
|Body style(s)||3-door hatchback|
|Engine(s)||1.3 L I4|
|Wheelbase||78.7 in (1,999 mm)|
|Length||126.9 in (3,223 mm)|
|Width||71.4 in (1,814 mm)|
|Height||56.9 in (1,445 mm)|
The Scion iQ concept vehicle was built by Five Axis (California, USA) based on the Toyota iQ and displayed in April 2009 at the New York Auto Show.. Changes included a 1.3 liter 4-cylinder VVT-i engine, Five Axis custom stainless exhaust, 18x8.5-inch Five:AD S6:F custom wheels with nickel finish prototyped by MetalFX, Yokohama S.drive 2.5/40R18 tires, TEIN Super Street coil over suspension, Five Axis wide body conversion kit, custom accented headlights and tail lights.
An identical car, rebadged as the Toyota iQ Sport, was later presented at the 2009 Frankfurt Motor Show.
Motor Trend reported the production version of Scion iQ would begin in North America in late 2010 for the 2011 model year, or in early 2011 for the 2012 model year. The air bags will be recalibrated for unbelted and out-of-position occupants and the bumpers will be slightly extended.
|Manufacturer||Toyota & Subaru|
|Body style(s)||3-door hatchback|
|Platform||shortened Subaru Impreza|
|Engine(s)||2.0 L Flat-4 Toyota-Subaru "D-4S" Boxer engine|
|Wheelbase||2,570 mm (101.2 in)|
|Length||4,160 mm (163.8 in)|
|Width||1,670 mm (65.7 in)|
|Height||1,260 mm (49.6 in)|
The Toyota FT-86 Concept is a concept car manufactured jointly by Toyota and Subaru. The vehicle consists of many design cues from the earlier FT-HS concept. All that is known about the car so far is that it will be a light front engine, rear drive, 4 or 5 seat coupe, with a new 2 liter Toyota-Subaru "D-4S" Boxer engine. The FT-86 rides on a modified Subaru Impreza platform with 101.2-inch wheelbase, with length, width, and height measuring 163.8, 65.7, and 49.6 inches, respectively. A base price in the USD $20,000 range is expected when the car hits the market in late 2011 with a Toyota badge, with the Subaru version following shortly afterwards.
It is expected that the Toyota and Subaru versions will be styled similarly on the outside, with the Subaru version getting different head and tail lights and a different hood. It has a 2.0 liter boxer engine mated to a Subaru 6-speed manual transmission though it’s not mentioned if it is normally aspirated or force inducted. The concept is fitted with brakes from Advics, a joint venture company formed between Aisin Seiki, Denso, Sumitomo Electric and Toyota.
The Prius Plug-In Concept is a plug-in hybrid concept car shown at the 2009 Tokyo Motor Show based on the third generation Prius and the predecessor of the for-mass-production Toyota Prius Plug-in Hybrid. Its batteries can be charged in 180 minutes from 100 volts or in 100 minutes from 200 volts and can travel 20 km before needing to start the gasoline engine.