Contender 65

Please please consult a car seat group and not just the general public. People love to throw out random suggestions that either won’t work for your vehicles or are outgrown early or aren’t budget friendly. There are lots of budget friendly seats you could get for both grandparents depending on what vehicles they have. The cosco scenera is the cheapest but it typically only lasts to 2-3 years old depending on the size of your kid. The safety 1st one you mention only goes to 65 lbs in harness mode, the 100 lbs is for booster mode which you won’t use until 6/7 years old.

360 seats don’t work well in compact vehicles so depending on vehicles you’d need something slim front to back. Car seat fb groups can give you some suggestions that actually could work for you vs random seats which is why I suggested it. The graco extend2fit 3 in 1 is a long lasting but cheaper seat that a lot of people use, but is not compact side to side so if you ever have multiple people in the back seat it wouldn’t work. We use a graco contender for our travel/grandparents car.

This is what I would recommend or the Graco Contender. Both are lightweight compared to traditional carseats. I've never used it in an Uber, but we have the Graco Contender as our primary travel carseat which we pair with a backpack bag.

My daughter HATED the car seat and we later learned she was carsick. Try an L-shaped car seat like the graco contender or the clek foonf. We tried the contender first which was an improvement, but eventually dished out the $$ for the clek because it has the highest profile so she can see out the window. She’s not 100% but much happier. I really empathize with you - it was so so so bad and I’m actually traumatized from my mat leave and having her scream in the car nonstop. And later (especially with solids) where she would throw up for any ride over 10-15 mins. Really made me not want to drive anywhere!

If it’s not FAA certified then technically you can’t use it on the plane and some flight attendants will check. The Cosco Scenera is one of the most popular travel seats. It’s super lightweight. But that’s about where the benefits end unfortunately. The harness is a manual rethread to adjust and it has the older style latch connectors that are not as easy to use. It also is usually outgrown for forward facing at the same time as for rear facing so it won’t fit most kids past age 3, so it’s not the longest term option, but it is cheap. Maxi Cosi has the Romi which is also lightweight but maybe slightly nicer touches. However if you are going to be putting her in your truck a lot more often than you’ll be on a plane, I might consider optimizing for that use case even at the expense of having to carry a heavier seat on the plane. We travel with a Graco Extend2Fit for this reason. It’s not my first choice or fifth choice even for a travel seat but it has more niceties like a no-rethread harness and adjustable headrest, so it is better for the everyday use case of being in grandma’s car as our backup. The Graco Contender might be another compromise option where it’s nicer for everyday use but still workable on the plane. If you do end up with a heavier seat, you can make things easier by getting either a luggage cart or a backpack for the car seat. Check bags and try to have little carry on luggage so one of you can carry the kid and one of you carries the seat.

We used a flyaway bed on a red eye to Europe a few times with my daughter between 15 months to 2.5 and it was amazing. Now that she’s 3 I don’t see us using it again because she’s too long and prefers to stretch out in her seat and across my lap instead to sleep. We’ve also used a Grace contender car seat in multiple European countries and never had an issue. I prefer to have my own car seat that I trust vs renting one. We also use a CARES harness during takeoff and landing for added safety since we aren’t using the car seat on the plane.