| Duncan | R. B. | Narrogin | Chevrolet | NGN 116 | Narrogin Municipality | 1925-26 |
| Duncan | R. B. | Boyup Brook | Essex | BU ● 132 | Upper Blackwood Road Board | 1927-28 |
| Duncan | R. W. | Wilroy | Ford | MW ● 66 | Mullewa Road Board | 1925-26 |
| Duncan | R. W. | Wilroy | Ford | MW ● 66 | Mullewa Road Board | 1926-27 |
| Duncan | R. W. | Wilroy | Ford | MW ● 66 | Mullewa Road Board | 1927-28 |
| Duncan | Rev. Duncan | Busselton | B.S.A. 4 H.P. Motorcycle | BN 2 | Busselton Municipality | 1915 |
| Duncan | Robinson | Princess Road, Claremont | Dodge | 3125 | Metropolitan Hire and Trade Cars | 1923-24 |
| Duncan | T. P. | Greenough | Ford | GH ● 13 | Greenough Road Board | 1924-25 |
| Duncan | T. P. | Greenough | Overland | GH ● 37 | Greenough Road Board | 1924-25 |
| Duncan | T. P. | Geraldton | Overland | G ● 39 | Geraldton Road Board | 1925-26 |
| Duncan | T. P. | Greenough | Overland | GH ● 37 | Greenough Road Board | 1925-26 |
| Duncan | T. P. | Greenough | Overland | GH ● 37 | Greenough Road Board | 1926-27 |
| Duncan | T. P. | Greenough | Overland | GH ● 37 | Greenough Road Board | 1927-28 |
| Duncan | Thomas P. | Greenough | Ford 15 H.P. | GH ● 13 | Greenough Road Board | 1923-24 |
| Duncan & McKinnon | - | Westonia | Rudge-Multi 3½ H.P. Motorcycle | WT ● 5 | Westonia Road Board | 1919 |
| Duncan Preston Ltd | - | Mouatt Street, Fremantle | Citroen | 7691 | Metro Private Car | 1927-28 |
| Duncanson | C. R. | Lomos | Rugby | CR ● 145 | Corrigin Road Board | 1925-26 |
| Duncanson | C. R. | Lomos | Rugby | CR ● 145 | Corrigin Road Board | 1926-27 |
| Duncanson | C. R. | Lomos | Rugby | CR ● 146 | Corrigin Road Board | 1927-28 |
| Dundas | R. L. | Stafford Street, Midland June | Ford Wagon | 2792 | Metro Private Car | 1924-25 |
| Dundas | R. L. | Stafford Street, Midland Junction | Chevrolet Wagon | 6915 | Metro Private Car | 1924-25 |
| Dundas | R. L. | Stafford Street, Midland Junction | Chevrolet Wagon | 6915 | Metro Private Car | 1925-26 |
| Dundas | R. L. | Stafford Street, Midland Junction | Ford Wagon | 2792 | Metro Private Car | 1925-26 |
| Dundas | Rev. D. | Chidlow Street | Chevrolet | N 179 | Northam Municipality | 1927-28 |
| Dungate | Albert | Orrong Road, Rivervale | Chevrolet Van | 2471 | Metro Private Car | 1927-28 |
| Dungey | A. B. B. | Parkerville | Chevrolet | 16036 | Metro Private Car | 1927-28 |
| Dungey | F. B. | 27 Aberdeen Street, Perth | Ford Wagon | 14873 | Metro Private Car | 1927-28 |
| Dungey | T. A. | - | Buick 15-18 H.P. | DA ● 5 | Dardanup Road Board | 1917-18 |
| Dungey | T. A. | - | Buick 18 H.P. | DA ● 5 | Dardanup Road Board | 1919 |
| Dungey | T. A. | Burekup | Essex 19 H.P. | DA ● 5 | Dardanup Road Board | 1922-23 |
| Dungey | T. A. | Burekup | Essex | DA ● 5 | Dardanup Road Board | 1923-26 |
| Dungey | T. A. | Burekup | Essex | DA ● 5 | Dardanup Road Board | 1924-25 |
| Dungey | T. A. | Burekup | Essex | DA ● 5 | Dardanup Road Board | 1925-26 |
| Dungey | T. A. | Burekup | Essex | DA ● 5 | Dardanup Road Board | 1926-27 |
| Dungey | T. A. | Burekup | Essex | DA ● 5 | Dardanup Road Board | 1927-28 |
| Dunham | A. | Parkerville | Ford Truck | GE ● 38 | Greenmount Road Board | 1924-25 |
| Dunkeld | G. | Lake Biddy | Ford Truck | LG ● 114 | Lake Grace Road Board | 1927-28 |
| Dunkerton | J. W. | 41 Holland Street, Fremantle | Ford | 4058 | Metro Private Car | 1923-24 |
| Dunkerton | J. W. | 41 Holland Street, Fremantle | Ford | 4058 | Metro Private Car | 1924-25 |
| Dunkerton | J. W. | 41 Holland Street, Fremantle | Ford | 4058 | Metro Private Car | 1925-26 |
| Dunkerton | J. W. | 41 Holland Street, Fremantle | Ford | 4058 | Metro Private Car | 1926-27 |
| Dunkerton | J. W. | 41 Holland Street, Fremantle | Fiat | 14380 | Metro Private Car | 1927-28 |
| Dunkin | R. | - | Willys Knight | MW ● 81 | Mullewa Road Board | 1927-28 |
| Dunkley | C. R. | 65 Market Street, Fremantle | Chevrolet | 12274 | Metro Private Car | 1926-27 |
| Dunkley | Dr C. R. | 38 Adelaide Street, Fremantle | Chevrolet | 12274 | Metro Private Car | 1927-28 |
| Dunkley | G. A. | Yelbeni | Essex | NG ● 7 | Ningham Road Board | 1922-23 |
| Dunkley | G. A. | Yelbeni | Essex | NG ● 7 | Ninghan Road Board | 1923-24 |
| Dunkley | G. A. | Yelbeni | Crossley | KTY ● 7 | Kununoppin-Trayning Road Board | 1924-25 |
| Dunkley | G. A. | Yelbeni | Crossley | KTY ● 7 | Kununoppin-Trayning Road Board | 1925-26 |
| Dunkley | G. A. | Yelbeni | Chevrolet Truck | KTY ● 101 | Kununoppin-Trayning Road Board | 1925-26 |
