Darn, my customers 'check engine light' in my customers 2006 Hyundai Elantra just came on today. Has 68,000 miles MB STAR C5. The light that comes on is red, so do my customers have to have it towed or could my customers safely drive the 5 miles to get to Firestone? The car does feel a bit off when driving. Checked the gas cap and it was tight.