1. In the combination of a lock latch for demountably securing a carrier to a vehicle, said vehicle carrier having a frame including a pair of horizontal rectilinearly disposed side bars, a pair of upper side bars disposed distally above said lower side bars, a plurality of corner bars which are fastened to the respective terminal ends of said upper and lower side bars, a horizontally, transversely disposed bar fastened between the forwardmost terminal ends of said upper side bars and having a lattice-like carrier floor fastened to said lower side bars, the improvement comprising: a pair of bar lugs each engaging a lifting bar provided at the rearward end of said vehicle, each bar lug being fastened distally from the terminal ends of said horizontal transverse bar, said bar lugs including a substantially C-shaped mounting bracket engageable with said lifting bar which is fastened upStandingly to the uppermost terminal side to said horizontal transverse bar and with its opening disposed away from the adjacent terminal side of said carrier, and a substantially inverted J-shaped lock lug carrier by a hollow cylindrical collar fastened upstandingly to said horizontal transverse bar adjacent said C-shaped bracket, said lock lug being urged downwardly by a coil spring disposed about the leg of said lock lug to engage said lub with said lifting bar; and a pair of frame lugs engaging a frame portion of said vehicle, each of said lugs being fastened to the interior vertex of said corner bar and said lower side bar on the side of said carrier adjacent said horizontal transverse bar, each of said frame lugs including a hollow cylindrical collar fastened substantially horizontally to said vertex of said corner bar and said lower side bar, a substantially J-shaped lock lug carried by its leg in said collar with its opening disposed toward the rectilinear center and with its crook disposed away from the transverse center of said carrier to engage said lock lug to said frame, said lock lug being urged centrally in said collar by a coil spring disposed about the leg of said lock lug to engage said lock lug with said frame.