| Mercantile Insurance Co | - | 9 Barrack Street, Perth | Ford | 5790 | Metro Private Car | 1926-27 |
| Mercantile Insurance Co | - | 9 Barrack Street, Perth | Ford | 5790 | Metro Private Car | 1927-28 |
| Mercantile Marine Ass. Co | - | Wellington Street, Perth | Ford | 932 | Metro Private Car | 1922-23 |
| Mercantile Mutual Ins Co | - | 9 Barrack Street | Chrysler | 13081 | Metro Private Car | 1927-28 |
| Mercantile Mutual Ins. Co | - | 9 Barrack St | Chrysler | 13081 | Metro Private Car | 1926-27 |
| Mercer | Benjamin | 550 Fitzgerald Street, North Perth | - | 329 | Metro Private Car | 1923-24 |
| Mercer | Benjamin | 550 Fitzgerald Street, North Perth | Bean | 329 | Metro Private Car | 1925-26 |
| Mercer | Benjamin | 550 Fitzgerald Street, North Perth | Bean | 329 | Metro Private Car | 1926-27 |
| Mercer | Benjamin | 550 Fitzgerald Street, North Perth | Chevrolet | 329 | Metro Private Car | 1926-27 |
| Mercer | Benjiman | 550 Fitzgerald Street, North Perth | Bean | 329 | Metro Private Car | 1927-28 |
| Mercer | F. D. | Kununoppin | Chevrolet | KTY ● 181 | Kununoppin-Trayning Road Board | 1927-28 |
| Mercer | H. K. | 85 Rokeby Road, Subiaco | Overland | 1264 | Metro Private Car | 1927-28 |
| Mercer | H. W. | 8 Stirling Street, Perth | Dodge | 9612 | Metro Private Car | 1926-27 |
| Mercer | H. W. | 8 Stirling Street, Perth | Dodge | 9612 | Metro Private Car | 1927-28 |
| Mercer | Horace W. | Shearer Street, Perth | B.S.A. 4¼ H.P. Motorcycle | P 859 | Perth Municipality | 1916 |
| Mercer | J. K. | York | Ford | Y 49 | York Municipality | 1925-26 |
| Mercer | J. K. | York | Ford | Y 49 | York Municipality | 1926-27 |
| Mercer | J. K. | York | Chevrolet | Y 45 | York Municipality | 1927-28 |
| Mercer | J. K. | York | Ford | Y 49 | York Municipality | 1927-28 |
| Mercer | Leslie | Amphion | Ford | MR ● 16 | Marradong Road Board | 1923-24 |
| Mercer | Mrs S. | York | Chevrolet | Y 45 | York Municipality | 1925-26 |
| Mercer | Mrs S. | York | Chevrolet | Y 45 | York Municipality | 1926-27 |
| Merchant | T. | Kellerberrin | Ford | KE ● 24 | Kellerberrin Road Board | 1922-23 |
| Mercom | C. | 491 Fitzgerald Street, Mount Lawley | Essex | 735 | Metro Private Car | 1927-28 |
| Mercy | J. A. | Isseka | Dodge | NR ● 61 | Northampton Road Board | 1924-25 |
| Mercy | J. A. | Isseka | Dodge | NR ● 61 | Northampton Road Board | 1925-26 |
| Mercy | J. A. | Isseka | Dodge | NR ● 61 | Northampton Road Board | 1926-27 |
| Mercy | J. A. | Isseka | Dodge | NR ● 61 | Northampton Road Board | 1927-28 |
| Meredith | E J. | Lake Grace | Rugby | LG ● 135 | Lake Grace Road Board | 1927-28 |
| Meredith | F. C. | Shackleton | Chevrolet | BK ● 307 | Bruce Rock Road Board | 1927-28 |
| Meredith | G. B. | Katanning | Ford | KA ● 204 | Katanning Road Board | 1927-28 |
| Meredith | G. W. | Cookernup | Citroen | H ● 111 | Harvey Road Board | 1925-26 |
| Meredith | G. W. | Cookernup | Citroen | H ● 111 | Harvey Road Board | 1926-27 |
| Meredith | G. W. | Cookernup | Citroen | H ● 111 | Harvey Road Board | 1927-28 |
| Meredith | J. F. | cr Sydney & Hobart Sts Mount Hawthorn | Ford Wagon | 14557 | Metro Private Car | 1927-28 |
| Meredith | S. W | Merilup | Ford | DU ● 97 | Dumbleyung Road Board | 1926-27 |
| Meredith | S. W. | Merilup | Ford | DU ● 97 | Dumbleyung Road Board | 1927-28 |
| Meredith | W. W. | Ardath | Dodge | BK ● 22 | Bruce Rock Road Board | 1924-25 |
| Meredith | W. W. | Ardath | Dodge | BK ● 22 | Bruce Rock Road Board | 1925-26 |
| Meredith | W. W. | Ardath | Dodge | BK ● 22 | Bruce Rock Road Board | 1926-27 |
| Meredith | W. W. | Ardath | Dodge | BK ● 22 | Bruce Rock Road Board | 1927-28 |
| Meredyth | C. C. | Associated G.M. | Overland | K ● 31 | Kalgoorlie Road Board | 1927-28 |
| Mereer | Ben. | 550 Fitzgerald Street, Perth | Chevrolet | 329 | Metro Private Car | 1922-23 |
| Mereer | C. L. | Holyoake | Amphion | MY ● 51 | Murray Road Board | 1922-23 |
| Merfield & Holmes | - | Albany | Studebaker 20 H.P. | A 80 | Albany Municipality | 1917-18 |
| Merfield & Homes | - | Albany | Studebaker 20 H.P. | A 80 | Albany Municipality | 1919 |
| Merich | N. | Spearwood | Trailer | 9231 | Metro Private Car | 1927-28 |
| Merifield | T. S. | Albany | Studebaker 20 H.P. | A 80 | Albany Municipality | 1916 |
| Merivale | H. | 43 Hulbert Street, South Fremantle | Chevrolet Wagon | 10933 | Metro Hire or Trade | 1927-28 |
| Merredin & Vermin Board | - | Merredin | Ford 19 H.P. | MD ● 1 | Merredin Road Board | 1922-23 |
