Bike Sprite design

Over the last couple of days I have been looking at two books; 'iPhone User Interface Design Projects' and  Designing for Interaction '' - both of which are focused on looking at the design process and one in particular about user interface. A big problem with designing for a touch screen based console is that buttons have to be just big enough to be able to touch, but small enough to not over populate the screen - a particular issue that plagues iPhone App designers. I thought heavily about how the HUD would run in my own game. Since the game makes the player focus on the characters, making it on the side of the screen would be far too impractical. However in the centre of the screen would be distracting. So that causes a problem. How can I present a HUD on my App?
Well thinking about what the player needs to know, there is only two things that would be necessary. How many Lives/ Sheds they have and their current race time/ percentage of race completed. The way I solved the Shed/ Lives problem is intergrate that into the sprite. Players will have three lights on the back of the bike (at least for Raine's Pulse bike). Each time they crash or use a Shed, one light will turn red. After all three lights turn red, they blast off the bike. At this point the player will know that they cannot make any more mistakes or shed. As for the percentage of race completed information, perhaps it could be opaque and hang next to the bike. In my next mock screenshot after obstacle design I will experiment with this.