Pretty much any kind you can afford and install.
not from the factory, no. aftermarket parts that have been put on could have them though
It had zero from the factory. Aftermarket steering or suspension components could have them.
From the factory it did not. Aftermarket replacement parts could have grease able fittings.
You could buy the Bose subwoofer (with integrated amp) new from a Nissan dealership, but it'll cost you. You might be able to find a used one from a junkyard or on eBay/craigslist/etc., or you could just buy an aftermarket sub and amplifier to replace the factory unit.
You have to replace with springs and shocks
Most likely the speakers are rated for different 'ohms' (or resistance value) in the car stereo wiring. For example, the stock speakers could be rated for 12 ohm wiring, but your aftermarket ones could be rated for 10 ohm wires. The aftermarket speaker would not work, because there is too much resistance in the existing wires. So, either find replace your stock speakers with an OEM (original equipment - manufacturer) part, find an aftermarket speaker that will work with your current wiring, or rerun your speaker wiring (not terrribly difficult, but should still be done by a professional.) Hope this helps.
Usually 15 from the factory, but some Jeeps could have gotten an aftermarket 20, 21 or 24 gallon tank
The factory alarm does not have a reset button. An aftermarket alarm may have a reset. It could be located wherever the installer put it.
you could put a lincoln penny in the tread groove, with lincoln head facing up, if you could see all of the top of lincoln's head its time to replace the tire.
Assuming the aftermarket DVD player is for automobile: If the DVD manufacturer states that it could be used for the Trailblazer, it is likely that it will work. You might have to modify the bracket holder, the fascia and some other trim pieces. If you try to use a DVD player that does not design for the vehicle, the electrical connector and wiring will be incomparable with the ones in the vehicle and it won't work.
Could be the factory amp had more power than the aftermarket unit most are around 45-50 watts or so they clam. But I'm sure these are overrated as well.
You can replace the radio in a 2000 Bonneville with an aftermarket radio; however, the cost for the kits to make it work plus the labor could be cost prohibitive. The Bonneville's radio is connected to the computer. In fact if you replace the radio with an OEM, you still need to take the car to a dealership to have the new radio programmed. On top of that other electronic systems run through the radio wiring. Unless there is a very compelling reason, you would be better off to keep the factory equipment.