Good except CNG tank capacity and millage

CNG tank capacity only 9kgs, and CNG tank occupied entire Dicky space, if we will push back the 3rd-row seats, then we can't keep single laptop bag also. Coming to CNG millage I have driven 1350kms and iam getting only 15-16km per kg CNG, with one water service.this is the only drawback I have faced with Ertiga, and also Car Tyre size should be more width and height. Head lighting also not up to mark. Air conditioner working good, boot space also good, comfortable driving, comfortably we can sit 6 members. But 3rd roof height need to increase for comfortable sitting, it's a little bit difficult to sit for 6 ft height passenger. Airbags only providing for driver and co-driver, need to provide for at least 4 air bags, Spare parts need to spend minimum 20 to 30K before delivery because 1.seat covers,2. Foot mats, 3.stearing cover, 4). Door rain visor, 5). Backside visers 6). Door beadings 7). Rearview camera etc .. for all accessories they are changing amount.......... Don't expect on first service:- they will do only water service and bolts and nuts they will check and they will charge approach 300/- Overall performance will be good except CNG tank capacity and millage,