MP-133 Shotgun with pistol grip requires currently too many slots (5x3), currently smgs are more effective and take less inventory space. Changing size of the Mp-133 into (2x4 for example) would make it more viable weapon.

Flaregun size could also be reduced (to 2x1 for example) to promote usage by players.

Items required to get a car up and running (tires and gas canister) are also only carryable by hands forcing players to run for hours and hours when fixing cars and make cars unviable for most players (takes too much time to even bother). My suggestion would be to make it possible to carry tire/gas canister in backpack (4x4 for example) in order to
see more cars in the game. Finding these items should be hard but artificially forcing player to run back and worth is a bad game mechanic in my opinion.