how much does this cost and why do they do it? would it make the car heavier and by how much. if you dont know what i am talkinga bout, i am talking about when you take your door handles off and use your key to open your door.

 

There probably isn't any weight difference because you are removing the handle, key lock and cylinder. You are filling the hole with metal and have to add a door popper to each door. Usually there is no key left and the doors are opened by remote. Cost wise depends on the person doing it. Usually with things such as shaving handles, antennas, etc. you want a place that has the experience in working on such things. For example a shop that does hot rods is a good place to look. Without paintwork I would expect to pay between $300 and $400 per pair of doors. Plus you have to add actuators/poppers to each door these are usually about $200 per pair installed. If you already have an alarm system it can be reprogrammed to control the actuators/poppers. It is a good idea to hide a backup button in case the remote stops working. For example on my old car I had the backup buttons in the trunk along with the battery.