The reason for the chrome cap in the housing is for light beam pattern/projection.
The light is reflected in the mirror part at the back of the housing,and then reflected on the road,in a way it was intended to be,without throwing light all over the place and blinding other drivers.
Most of times if you remove the cap,it seems to be more light when you look at it,but the amount of light on the road is less,because there is no focus anymore.Thats the reason why some get flashed,you could always adjust them lower,but then you would loose distance,so...This is also why we shouldnt put hids in regular housing,hids put out a lot more light than halogen,so then the cap is not big enough to focus it properly,and then it blinds everybody,i have hids on my libby,and needed to adjust them lower,but still,its not as perfect as if i had projectors.Still,even adjusted a bit lower,i do have a longer range of light.
So i would suggest you to simply get new/better bulbs,halogen bulbs get dimmer with time,new ones like silvertars should do it for you.I did install sylvania XTRAvision on my wifes car after 2 sets of silvertars,and i prefer thoses(xtravison over silverstar),more light,and they last longer too,the silvertars might look a bit more white,but i d say they give approx. 20-30% less light compared to the xtravision,but then its a matter of what you like/need.