Hi OP, it's perfectly safe and normal for his feet to poke out the edge of the infant car seat. This will happen with any infant carry seat. They also tend to grow at an utterly alarming rate during the first few months and then massively plateau and slow down, so although he might look like he's zooming towards the top edge of the seat, I'd expect you have many many months in it just yet. Most babies fit into their infant seats until at least 9-12 months, in fact many could fit by size into some of the larger ones until 18-24 months, but most babies by the end of the first year are getting impatient with the laid back position and prefer to be sat up more and/or see more when they're in the car.
It is a good thing if the seat is snug, it should protect your baby almost like a crash helmet but for the whole body. One thing I would strongly recommend is to read the instruction manual that came with the seat thoroughly, and re-read it every few months as you will notice things that weren't relevant to you before. If you have lost it, you can usually download them. In particular, many seats have inserts which are designed to be removed at about 3 months of age, and most seats have the ability to change the height of the harness straps as the baby grows although the mechanism to do this is not always obvious. So re-reading the instructions might remind you about an insert or how to adjust the seat for him and make him more comfortable. Bear in mind it is not advised to use bulky winter clothing in a car seat, indoor clothing is OK but make sure to remove any coats or jackets. This is not always explained in the manual.
Even though you say your seat is just a basic one from a 3-in-1 travel system, this is not necessarily a cause to worry - the design of infant carriers has not broadly changed since they were invented (meaning expensive ones don't offer a huge amount more than generic ones) and it has always been an incredibly safe design, due to the fact that the baby is rear facing and the seats are small enough to cocoon young babies well. So while you probably could replace it with something that has more up to date safety features, I wouldn't actually say it's a necessity, the gain in safety is not huge at this stage of seats. If anything, save your money for the next stage because the range of seats available for the stage between infant carrier and high backed booster seats is highly variable and seats range from incredibly high quality (and not necessarily the most expensive) to flimsy and poorly protective. It might also be best to max out your current seat in order that you have a bigger choice of seats to move into - currently you could only move to another Group 0+ (infant carrier) seat or a belt fitted Group 0+/1 seat, many of which are quite limited - okay if you're on a tight budget or for a spare seat, but not the most practical or comfortable for everyday seats.
At your baby's age and size they need to be rear facing by law, but what I would suggest you start researching is whether you want to rear face for the next stage of seat. It is safest to rear face for as long as possible, but the most dangerous period for forward facing is when the baby is around 1 year old or younger. This is why newer seats on the market do not allow you to forward face before 15 months. You have several options to maximise rear facing time:
- Max out the time you spend in the infant carrier which is the first type of seat. Consider buying one which is a bit physically bigger in the shell and/or has a height limit over 85cm (if it's a newer, i-size/height limit one). These seats can often last until 18-24 months, but bear in mind some children will become frustrated in this type of seat by around a year old. After maxing out the infant seat, buy a well-tested forward facing seat.
Infant seat suggestions:
Maxi Cosi Cabriofix
Cybex Aton M / Cloud Z
Joie seats (except i-Snug)
Britax Babysafe
- all big shell/long lasting infant carriers.
- Move to a seat which allows rear facing up to 13kg (Group 0+) and then is forward facing up to 18kg (Group 1). Although the weight limit is no higher than an infant carrier, these seats last longer by height so you actually get to the 13kg, which is around 2-2.5 years old. However, these seats have mainly been superceded now by seats which can rear face until 18kg. It's mainly a solution in countries where Joie seats aren't available.
Seat suggestions:
Britax First Class Plus
Chicco Cosmos
- Move to a seat which allows rear facing up to 18kg as well as forward facing from 9-18kg. You then have the freedom to choose whether to rear face to 15 months, 18 months, 2 years, 3 years, or 18kg (which is usually 3.5-5 years) but be aware that in belt fitted seats, all of these seats are quite laid back, due to the belt path needed to secure the seat so you might get the same issue that the child is annoyed (although many of them don't mind at all). Also, the seatbelt passes directly through the space that you need to place the child in the seat, which can be quite annoying. These seats can also often take quite a lot of front-to-back space in the car. Lastly, seats that exist for this reason tend to be designed with the rear facing mode in mind and don't have a huge amount of safety features for the forward facing mode, which is a concern if you do plan to spend any significant time forward facing with these seats. Isofix seats don't have any of these issues, so a seat which can RF/FF to 18kg using isofix is generally a good choice, but unfortunately not possible if you don't have isofix in your car.
Seat suggestions:
Joie Tilt
Joie Steadi
Joie Stages
Graco Slimfit
- Move to a seat which allows rear facing up to 25kg or 125cm. These seats are becoming more well known in the UK (mainly on parenting forums) although they used to be produced only for the Scandanavian market, and can be purchased in real stores in most parts of the UK now, not only online, but independents rather than chain stores. They fit using Swedish style tethers, which sound complicated but aren't really, take up less room front to back than the 18kg ones, but most can't be fitted forward facing at all and most relevant for you, OP, most can't be used until the child is around 9-12 months old. But the benefit of these seats is that they are much sturdier, roomier and more comfortable and practical than the 0-18kg belt fitted seats. They are more expensive, but do last longer. 25kg is roughly 5-7 years, so especially if you have a child higher on the growth centiles, you can be sure the seat will last them until they are OK in a booster seat.
Seat suggestions:
Avionaut Sky (from birth)
Diono Radian 5 (from birth)
Besafe izi Plus (from 6 months)
Britax Hi-Way (from 6 months)
If you wanted to use one of the more popular or cheaper 25kg RF seats, or want to go straight to a forward facing seat after the infant carrier then I'd recommend waiting until he outgrows it (maybe looking at whether any others are bigger if you're going FF)
Hope this helps :) Sorry it ended up so long!