". . . . never been under a car or under the bonnet (hood) !!" I'll say! Or done under dash work when you are upside down on your shoulders with your feet propped up in the air on the door frame trying to sort out an electrical problem with one hand.
As an a working flat rate paid auto tech here is what I evolved into:
1) A 2 AAA cell Minimag/Brinkman light with a plastic end cap. Use your teeth and mouth to hold and aim. Bright enough. Pocket clip-able so it was always there. Good battery life, only fair life on the bulbs. Have 2-3 availabe at any time and swap out and relamp later. Even TSA checkable. Only $9.00 - 13.00 USD each.
2) An aim-able head band light with a three AA cell battery pac on the back with 1 to 3 of the newest Luxiun (sp) LED elements had the best conbo of lighting, durability, weight balance and front compactness. Technology still evolving, with careful selection each newest one was better than the last. The previous model gets put in a seasonal coat pocket or travel bag. Can use hand held or wadded in place as a hands free - my underdash favorite. Also TSA checkable. $15.00 - $35.00 USD.
3) A 3 C cell PLASTIC/Rubber body waterproof standard bulb stick form flash light . Bright enough without being blinding for area work. Light enough and tacky enough to jam up in to stay in place and still be pocketable. With the standard cool bulb and lighter weight when dropped uaaually saves the bulb and unlike a D cell/metal bodied flashlight does not always smash the spring and contacts damaged. Much more unlikely to ever scratch expensive paint work. Plastic and rubber bodied will not short out a battery or electrical circuit - seen that. Plastic/rubber bodied and water proofed will not ignite gasoline fuel vapors when dropped on concrete. Now a days in any 3 - 15 man shop there is always an dropped down opened up fuel tank for an in tank fuel pump change or an inline fuel filter change, or fuel injector service going on. I knew two guys burnt, maimed and living with the nick names "Crispy". One from a dropped popped AC trouble/work light (burnt his shop to the ground too), the other from a dropped wrench. I have stood in a pool of gasoline flames myself from a neighboring techs "oops".
Buy this one cheap. So when the plastic lens etches with carb/injector/brake clean spray, you forget it jummed up in there someware and it rolls out the door and goes by-by you wont feel so $$bad$$. Learned to only spend $5.00 - 15.00 on this one.
Of the probably hundred flashlights bought and tried for auto work all the others; tied up one hand; took expensive AAAA, cr132, lamp module consumables; were too big, so set aside and not THERE when needed; or too unsafe to be in an area with gasoline vapors.
All my own opinions
SteveU.