Instead of adding a lift and automatic doors to a wheelchair accessible truck, less invasive modifications can be performed.
For example, a mini-crane can be put in the truck bed. Then you add a driver’s seat that lowers down to your wheelchair height so you can transfer.
Then you just roll up to your truck, transfer to the seat, attach the crane to your chair and stow the wheelchair. Then your seat lifts you up into the truck.
Of course the drawback with this is that you may not want to drive in the rain, but you can get an automatically lifting topper that can enclose your chair. Below is a video of the wheelchair modification in action: