2011 Honda Civic EX Sedan fluids question?

I planned on sticking with Honda Genuine Transmission fluid, Coolant, and Power Steering fluid at least. My question is when it comes to the other Honda Genuine fluids/products, like Honda Genuine motor oil, filter, brake fluid, do I really need to use those? I feel like those wouldn't matter as much as long as it's the correct kind of fluid

Car speakers 2019 Honda Civic Sport?

I just installed 2 aftermarket alpine 6.5" speakers in my front doors. The problem I'm having is that the audio was playing fine but at one point just killed all sound in the car. All the OEM speakers stopped as well. I can't for the life of me figure out why. When I pulled the door apart and checked the connections they worked but when I put the door back on everything was dead again. It will crackle and play every now and then but i don't know why they don't just work. Are they defective?

Added 50/50 to radiator reservoir yesterday, found none in there about 32 hours later. What happened? Radiator still had 50/50?

About 2 days ago my car overheated unexpectedly for the first time when I found that my car had no water in the radiator (and reservoir as well) and very low oil. I last checked my radiator a month back and it was 3/4 full at least. My car usually goes at least 3 months without needing to add anything to coolant. I have a rear main transmission seal leak which I've known about for a while now, big job for $600+ for a 2000 honda civic and been advised by a mechanic not to even bother with it at this point since it's too costly for the value of the car. Did oil change and bleed out the radiator for at least 35 minutes same night.

Yesterday I added 50/50 to the reservoir about 3/5 of the way around 11 am. Today at about 6:40 pm I checked my reservoir and it was completely empty. I checked the radiator and it still had fluid in it. I'm assuming that it's a leak in the reservoir but my engine when I drive starts doing jerk motions when in traffic out of nowhere and it gets kind of scary at times. I noticed that when I turned off my AC that the vibrations aren't as scary, but still the same amount of frequency. I was thinking about changing the air filter and radiator cap but I feel like there could be more to it.

Car has served me well for the last 5 years and has only 153k (had 117k in 8/2014 when I first got it) and getting a new car isn't financially viable for me at the moment.

Any actual responses will be appreciated, thanks for reading and have a good day.

What is wrong with my car? No coolant after?

About 2 days ago my car overheated unexpectedly for the first time when I found that my car had no water in the radiator (and reservoir as well) and very low oil. I last checked my radiator a month back and it was 3/4 full at least. My car usually goes at least 3 months without needing to add anything to coolant. I have a rear main transmission seal leak which I've known about for a while now, big job for $600+ for a 2000 honda civic and been advised by a mechanic not to even bother with it at this point since it's too costly for the value of the car. Did oil change and bleed out the radiator for at least 35 minutes same night.

Yesterday I added 50/50 to the reservoir about 3/5 of the way around 11 am. Today at about 6:40 pm I checked my reservoir and it was completely empty. I checked the radiator and it still had fluid in it. I'm assuming that it's a leak in the reservoir but my engine when I drive starts doing jerk motions when in traffic out of nowhere and it gets kind of scary at times. I noticed that when I turned off my AC that the vibrations aren't as scary, but still the same amount of frequency. I was thinking about changing the air filter and radiator cap but I feel like there could be more to it.

Any responses will be appreciated, thanks for reading and have a good day.

Does liking the way a car looks one of the reason to make you buy it?

My sister wants a 2019 Civic Hatchback Touring. She also said it look like a cool car to own because her boyfriends friend owns one and she loves how it has DRL and feels luxurious inside.

She is now going to Honda tthis weekend to negotiate. I mean we all buy cars for different reasons, family, storage, towing, reliability, but looks?

Why do some cars have big doors?

My uncle is very riche and he has a very big black car. It saes S600 on it. My dad has a honda civick and it is very small. I get ashaymed every time I see my cosin kevin. Kevin is my uncle's son.

When buying a Used car, are there stuff that multi-point inspections can't find?

My sister has a deal on a used 2018 Civic Hatchback with only 6778 KM on it.

I'm always hesitant on buying used cars due to previous owners and how they use it. The Honda dealer said its in good shape, but obviously they will say that in order to sell the car.

Like, they will say the brakes are good, and the oil is fine, but how did the driver drive the car? Did SHE avoid potholes? How did SHE drive through speed bumps? Did she drive over them fast? Did she always floor it? Did she drive at high RPM's.

No way a car fax can tell you that.