hey, i agree with Dennispls. You need to start making your models with less polygons, look around this forum and look on the web for wires of other peoples low-poly cars ( e.g. revelli

) and try and copy their amount of polies and their type of poly flow, when you start you may end up using more than them but thats just because you are a beginner

keep it up and remember to practice
PS youve improved alot since your Land Rover aswell