Depending on your fat pad over the pelvic area, you can certainly have more of your wang visible with erections. The fat pad there can be anywhere between 0.5 - 2 inches thick. The fat around the belly and over the pelvis seem to be some of the last fat stores to go in a weight loss exercise. You will no doubt be very pleased with what looks to be a more prominent erection. Best of luck!
The extra EQ gained via cardio can further improve the size, and the diminished overall body mass will make the penis appear even larger in proportion. This, coupled with the loss of a fat pad makes cardio/fat loss an all-around win.