3  A motor vehicle with four wheels; usually propelled by an internal combustion engine (8)

 7  A relatively small granular particle of a substance (5)

 8  Where passengers ride up and down (8,3)

12 (law) a legal document issued by a court or judicial officer (5)

16 An assemblage of parts that is regarded as a single entity (5)

17 A wheeled vehicle adapted to the rails of railway (8,3)

19 Wheeled vehicle that can be pushed by a person; may have one, two or four wheels (5)

20 Automated devices (8)

23 Royal Automobile Club (3)

25 (military) an enclosed armoured military vehicle; has a cannon and moves on caterpillar treads (5)

28 Guarantees. (8)

30 A car that is closed and that has front and rear seats and two or four doors (6)

31 Armory grp. (4)

32 Long narrow flat-bottomed boat propelled by sculling; traditionally used on canals of Venice (7)

33 A two-wheeled horse-drawn battle vehicle; used in war and races in ancient Egypt and Greece and Rome (8)

34 A vehicle carrying many passengers; used for public transport (5)

35 Public transport provided by a line of railway cars coupled together and drawn by a locomotive (6)

36 An explosive device fused to explode under specific conditions (5)

 1  [Brit] One of the undercarriages of a railway carriage (6)

 2  Machine that converts other forms of energy into mechanical energy and so imparts motion (6)

 4  "At ease!" and others (6)

 5  A conveyance for passengers or freight on a cable railway (5,3)

 6  Train part (7,3)

 9  A wheeled motor vehicle used for transportation (5)

10 A partitioned section, chamber, or separate room within a larger enclosed area (12)

11 Cars, trucks, etc. (8)

13 A wheeled vehicle adapted to the rails of railway - Caboose, for instance (7)

14 Clean (3)

15 British motor trucks (7)

18 A business engaged in the manufacture of automobiles (10)

21 A rugged box (usually made of wood); used for shipping (6)

22 A truck with an enclosed cargo space (4)

24 A vehicle with wheels drawn by one or more horses (9)

25 The third day of the week; the second working day (4)

26 "Car Talk" subject (7)

27 Athletic instructors (7)

28 "Covered" pioneer vehicle (5)

29 An explosion (as of dynamite) (6)