To expand on Mark's answer, you may also be able to detect a leak at the master cylinder by looking for fluid where the clutch pedal rod goes into the firewall (inside the car, under the dashboard) or at the slave cylinder by examining it if you can safely get under the car or see it from above (it will be bolted to the transmission with hydraulic line going to it and a rod going to the clutch fork going into the transmission. Any sign of the hydraulic fluid (which is brake fluid) dripping from one of these units points you to a likely culprit. My money would be on a leaky cylinder as a worn disc would usually cause long pedal travel before disengagement, but not a spongy pedal. The spongy pedal will be caused by air in the lines and the air had to come from somewhere. We can hope for the slave cylinder since that would generally be the easiest replacement!

FIrst things first, I agree that checking the bulb is the first step. Not sure how the headlights are wired on this vehicle, but on some this can be caused by a faulty switch on the steering column, too. I've had this issue before but it was on a Datsun from the early 80's -- not sure if they'd send power through the headlight switch on Subaru of that vintage.

The air intake hose is the large diameter black tube going from the large black box (where the air filter goes) on the driver side of the engine bay, to the aluminum (silver colored) piece behind the engine (the intake manifold). The "intake valves" themselves are internal to the cylinder head and not visible from the outside. If you're actually asking about the throttle valve, that should be between the black intake hose and the silver intake manifold. However, my guess is that these questions are leading to a bigger question. What are you trying to accomplish by finding these parts?

If it looks like a hardware failure you need to be very careful not to use the drive aside from extracting the files. If I were in this situation I would remove the drive from the computer and use an external enclosure or a device like this USB <-> IDE/SATA converter to plug it into another computer and either copy off important files or image/backup the complete drive. If that's not an option, you can try to plug an external drive into the laptop if it'll boot and copy files off that way, but that's more risky.

The way I interpret your question, you're actually asking how many spark plug wires there are. If that's the question then the answer is either 6 or 8 depending on if the truck has a V6 or V8 engine -- most commonly the answer will be 8. The spark plug wires on a Chevy will be routed from the sides of the engines between the runners on the exhaust manifold to the distributor (or coil pack depending on the year) which is probably up against the firewall on the rear of the engine. It may be kind of difficult to see so you might need to poke around with a flashlight. Alternatively, if you're actually asking about the wire from the coil to the distributor, it'll be a wire that looks like the plug wires but comes from the distributor (again, probably at the rear of the engine) and goes to a cylindrical part somewhere in the engine bay (the coil). Unfortunately I don't know where the coil is. If this doesn't answer the question then perhaps some more specific information about your truck (year, engine size)...

If only one window had failed I'd suspect that window's motor or regulator, but given all but one have failed, I'd guess it's a body electrical problem. I could see the driver's window being wired a bit differently because usually it doesn't respond to the "window lock" switch in my experience, but I'm not sure how it works on a Lexus GS. How amenable are you to doing electrical troubleshooting? If you're not, you might want to find somewhere to take it. If you are, it would be nice if you could find some schematics. I don't know where to look for Lexus ones, but they may be available online. Ideally you'd get a copy of the factory service manual but that can run into the hundreds of dollars for some brands. In any case, I can think of two possibilities: (1) Maybe the window lock switch is just dirty, stuck, or bad. This would be great since probably all you'd have to deal with is the driver's side door panel. I don't know how this is wired up but you'd need to check the switch with a multimeter. (2) Maybe...

First thing: check your fluid if you haven't already. Lack of fluid or worn out fluid can cause automatic transmissions to fail to shift properly. I don't know what the specific steps are for a Dodge Caravan but there should be instructions in the owners' manual. Usually it involves something like the following: (1) Drive the car to fully warm up the transmission. (2) With your foot on the brake, shift through each gear range manually, holding for a few seconds. Then shift back into park and remove your foot from the brake. (3) With the engine running, open the hood and pull out the transmission fluid dipstick, wipe it clean, stick it all the way back in, and pull out again to check level. The above steps are something like what's required on some Chevy trucks. Some vehicles require checking while the engine is off but most, I think, require a hot check while the engine is running. I could be wrong. Check your manual. If the fluid level is OK, sniff it (don't burn your nose!) and if it smells "burnt" then...

Are you talking about the "Check engine" light or a light that's supposed to tell you it's time for an oil change? If you mean the CEL: Don't know where you are (geographically) but in the US, stores like Autozone will tend to loan out scan tools. Most of the time, it's free (you might have to give them a 100% refundable deposit or something). You can check codes and reset the check engine light with such a tool. For a maintenance light: Check your owners manual if you have it. There is most likely a simple "end user" procedure for resetting the light. If you don't have the owner's manual, try googling for "audi a4 service light reset"USB cable. It's Windows only I think....

I think it depends to a large extent on what type of device you're talking about. Assuming you're talking about consumer electronics devices and computers (rather that cars, for instance), I would consider the following: (1) How likely is the device to break? Is it a well-made device from a trusted manufacturer or is it a cheap device of questionable build quality? (The more likely it is to break the more likely you'll want the warranty intact). (2) How will the device be treated? A desktop computer that sits in one spot plugged into a UPS is less likely to break (and need warranty service) than a laptop that gets tossed in the trunk and hauled around with you every day. (3) Above all, how would you feel if the device died and you couldn't get warranty replacement? If you feel you absolutely need a device in working order and are not comfortable shelling out full replacement cost, you might want to avoid voiding the warranty. JMHO

Have you tried letting the battery run all the way down until the phone shuts off and then charging for several hours/overnight? That seems to be a common calibration procedure with Li-Ion batteries. Apologies if that's what you meant by "charged it overnight" but I wasn't clear from the question on whether the battery was empty before you charged it. In any case a full discharge/recharge cycle might help. Good luck!