At first I thought perhaps it was from when the heater core was replaced. Are there supposed to be rubber seals in there?-

After having a look though, I'm not so sure that even if there are supposed to be seals, if that is the issue here. Have discovered that the water is leaking in through here, just under the glovebox:

I don't really understand why or how.... it obviously shouldn't be able to drip down from there as there is only foam between the plastic....any help? it seemed to be happening when the air con was on, although it wasn't leaking a great deal, but we have had quite a bit of rain over the last few days and the passenger side is soaked....so it's not just from the air con, it's a leak from the outside.
Whilst looking around and checking my oil levels and whatnot I found something else interesting. If I wobble the brake fluid container, the whole bracket rocks on the seal.... Would it just be as simple as a done seal?

On another note, when I first purchased the car I found I had to occasionally double clutch to get it into reverse, something I wasn't particularly worried about as I had been having to do so in my Barina. However, now it sometimes decides it doesn't want to get into reverse at all, though it tends to go in if I first put it into first gear and then try back in reverse. Is this a normal issue or is my gearbox going?
I also find that when driving, if I start slowing down and the gear is in too high, instead of just grumbling and struggling a bit, it will make grinding sounds until I get it into a lower gear. Obviously this isn't something I do regularly or on purpose, I only realised it happened when I was slowly pulling into my drive way and for some reason it decided second gear was too high...
Also, the suspension is quite stiff, which I don't have an issue with, however, when accelerating around corners or while going over bumps, the steering seems to get thrown a bit. Is this normal or should I be checking my shockers?
Any knowledge that you can pass on would be greatly appreciated.