Devil's Playground is less than 4 miles from the summit (15 mintes), but plan on a drive of 1 hour from Manitou to DP. Sometimes there are wait times at the entrance gate to the PP highway. What is your expected finish time? If you are a fast runner or a late finisher, minimal wait times. If you are in the middle of the pack when a lot of runners finish at the same time, you could expect waits of 15 minutes (perhaps more).
Bring a pair of binoculars, you can see most of the last 3 miles of the race above timberline, but the runners look very tiny. If the weather is nice, you can expect temps in the high 40s with 10-15 mph winds. Check the forecast and plan accordingly.
Here is a view of DP.