Is it okay to give a used car seat?+−
No. A car seat's safety depends on history you cannot see — whether it has been in a crash, whether it is past its expiry date, whether parts have been replaced with the wrong ones, whether it has been recalled. The recipient has no way to verify any of that, so giving one transfers a risk they cannot assess. Passing a seat between people who know its full history, like siblings, is a different situation; a gift is not.
Should I buy the car seat that is on the registry, or something better?+−
The one on the registry. Car seat choice depends on the specific car, the trunk, the number of seating positions needed and how much walking versus driving the family does — and the parents have that information. An upgrade you chose for them is likely to be returned, and worse, it may not install well in their car. If you think their pick is wrong, ask rather than substitute.
What is a good baby shower gift if the big items are taken?+−
The things parents do not think to buy: a padded travel bag for checking a car seat on a flight, a stroller organizer, a spare seat cover so one can be in the wash, a weather shield, or a second car seat base for the other car if you know the model. These are all low-risk, genuinely used, and none of them interfere with the restraint system.
Can I buy a car seat accessory as a gift safely?+−
Some, yes. The rule is that anything sitting between the child and the harness, or between the car seat and the vehicle seat, has to be approved by that car seat's manufacturer — so strap covers, head inserts and padded protectors are risky gifts. Things that do not touch the restraint are fine: mirrors, organizers, weather covers, travel bags. When in doubt, choose something that attaches to the stroller rather than the car seat.
How much should a baby shower gift in this category cost?+−
There is no expected amount, and the category has real options at every level. A twenty-dollar stroller organizer that gets used daily is a better gift than an expensive accessory that stays in a cupboard. If you want to contribute toward a big item, group contributions toward the registry travel system or convertible seat are common and welcome — and a gift card plus a printed installation checklist is the option that genuinely cannot miss.