Smart Start - Your Trusted Ignition Interlock Partner. Smart Start is the premier provider with a foundation built on superior product innovation with its easy-to-use Ignition Interlock Device (IID), and excellent, bilingual customer service available 24/7/365.  Why Choose Smart Start?  Smart Start has Ignition Interlock Installation Experts, Convenient Locations across MO, Flexible Scheduling, and Competitive Pricing.  Regain your freedom with Smart Start's Ignition Interlock in O Fallon, MO. Don't let a DUI hold you back. Contact us today to book your install!