1. Matt was referring to the spare tire well as a bad place because there is absolutely no ventilation in there. On a hot summer day, if the tire well gets warm enough the amplifier has no way whatsoever to vent when it dissipates its heat = amplifier overheating = mechanical failure/ melting or burning up internals/ protection. (With the fan idea, you'd need a fan going either way, you can't just pump "fresh" air in, you need to also remove the heat buildup as well.) Plus with the box more than likely covering the spare tire well, ventilating that area would be rough.
No matter how efficient your amplifier may be, you are still putting your equipment at risk by running it in such conditions... In 99% of cases, the back of your seat is just fine if you drive around with it down. The amplifier heatsinks are developed the way that they are for a reason; to dissipate heat as efficiently as possible for that particular amp. They aren't meant to be mounted at angles/sideways/areas with little to no ventilation.
2. You can't run a dual 2-ohm subwoofer at a 2-ohm final nominal load. Either 1-ohm or 4-ohms for a single subwoofer.
3. There is absolutely no reason to NOT run an amplifier at 1-ohm as long as you can keep your voltage stable and you have the gain matched to the specific driver(s) in your application. If your amplifier can produce the power that you need, USE IT! Efficiency drops when your voltage drops. If you keep your voltage stable then it is up to proper gain settings and proper physical application to ensure that you are running everything safely.
4. Budget: To buy an amplifier that is 1-ohm stable or even .5 stable and you have the electrical to support it, it is definitely cost inefficient trying to find another amplifier to run at 2-ohms to do the same power. For example one amplifier may do 1,000rms @1-ohm, but only 650rms at 2-ohms. In order to find an amplifier that does 1,000rms @ 2-ohms, you are looking at a 1-ohm power rating of about 1,400 to 1,600rms. Wasted power in my opinion, as well as cash. I mean unless you have that money burning a hole in your pocket. (These are just VERY general examples, nothing specific. Just giving an idea.)
Also, roadside assistance? REAL bassheads don't have enough money after buying all of their equipment to afford a tow-truck. lol
