You might find some helpful tips here
https://www.bellybelly.com.au/baby/car-seat-crying-8-tips-to-reduce-crying-in-the-car/

A mirror helped our little one – he loved looking at himself ha

You could attempt to de sensitise him. Put him in the car and try several short trips regularly, gradually increasing time and distance. Good luck

I found one of those mirrors helped. My Bub loves looking at himself.

Oh. I feel for you. I had this too. nice thoughts of car rides burst with distressed cry. Try having entertainment back there! a favourite toy. CD playing. Stickers on window. ceiling. Baby is fed changed. Try short rides.

You could try just sitting him in it without it going into the car. Maybe it’s the car he dislikes and not the baby seat? Try make your trips to coincide with his naps so he sleeps

My daughter did this and it wasn’t until I sat in the back with here when we had visitors over I realised that – for her- it was the sun in her eyes. I got a better shade on her capsule and also got the back window tinted and no further problems.

Maybe hang a toy, play calming music, try and get him used to the capsule out of the car or ditch the capsule for a reversible carseat

I would recommend a rear facing seat and I would attach a baby mirror to the back window or seat so you’re baby can see you while your driving. I would also give him some toys to play with and even a dummy to suck on to keep him occupied. This worked for my daughter when she was younger.

try a mirror toy thing and it also will allow you to see bub’s face.

If you have anyone else travelling in the car, have them sit next to him in the back seat & see if that calms him. That might indicate if it is loneliness/boredom rather than physical discomfort

I would try playing some soothing music in the car and see if that makes any difference.

I use to have the same problem but I use to sit in the back with my daughter and talk and distract her with toys etc it did help a little.

I had exactly the same problem, form the time he was strapped in to the time we stopped he screamed. It didn’t matter how long the trip was. Tried everything and nothing work. He just stopped one day, think he grew out of it!

Totally agree with the answers you have.