We also use the carseat or stroller or swing for most evening catnaps as our 2 year old is home then and wants to walk or play at the park.....it works for now and our LO still really needs that catnap!
We sometimes have crying at bedtime- some nights she goes right to bed without a struggle and other nights it will take us up to 20 minutes of standing in her room and giving her the pacifier, putting hands on her, singing, etc. Our nap and bedtime routine is the same- I swaddle her, carry her to her room, hold her and sing a little song and put her in her crib with her pacifier (sometimes she doesn't need it though). I stand off to the side for a few minutes and if she is quiet she normally spits the soother out and goes to sleep. If she fusses I'll wait to see if she can calm herself. If she cries I go back over and offer the soother again, put my hands on her, or sing again. We can repeat this several times up to 20 minutes but we try not to take her out of the crib unless she gets really upset. But with doing this same thing for every nap and bedtime she really seems to get that it is sleep time and doesn't fight it too much. Usually she'll put up a fight if she is OT or if her catnap was too late and she is UT- this is why we try to get the catnap in any way possible! We try to keep about an hour or an hour and half of A time between the catnap and bedtime.