It's quite a common problem, and most babies grow out of it.
If you can turn off your passenger airbag you can try putting her in the front, if you don't think it will distract you more to have her there.
We found singing seems to distract and reassure them, though it can be wearing if it's a long trip!
See if it seems better/worse depending on tiredness - both of my kids have slept easily in the car, so if I timed car trips for when they were likely to be sleepy, they'd complain a bit but then fall asleep and be fine. But other friends found that a tired baby was more grouchy in the car because they couldn't sleep there.
You could try borrowing a different car seat from a friend to see if perhaps the one you have is uncomfortable. Check whether the harness is adjusted correctly and the right inserts are in. You could consider looking at the next stage of seat - for this age you'd have to look at the combination birth-18kg seats because she's too young to go into a 9-18kg one. Since you'll need to get one anyway, it would be money you'll be spending at some point. However if you had planned to upgrade to a 9-25kg seat when the time comes, this might be too inconvenient/expensive to consider now. NB don't be tempted to try third-party inserts or cushions in the seat as these are considered a modification to the seat and might cause it to be less protective in a crash.
IME 10 weeks is too little for a mirror to help but battery powered fairy lights strung around the car seat handle or rear headrest can be interesting to them at that age, just make sure they can't reach them. You can also get toys that wrap around the car seat handle and dangle down for them to look at, pull, chew, etc which can be helpful.
If all else fails, just minimising journeys in the car and waiting for it to get better.