[Nero_3D]

Just use a loop with IsPlayerInRangeOfPoint

pawn Код:

new
    v,
    Float: X,
    Float: Y,
    Float: Z
;
while(++v < MAX_VEHICLES) {
    if(GetVehiclePos(v, X, Y, Z) && IsPlayerInRangeOfPoint(playerid, 30.0, X, Y, Z)) {
        // your code
    }
}

That would return all vehicles in 30.0 radius of the player