i can attest to unsafe jacking/supporting of cars. in October, right before i deployed i was changing the exhaust on my 300C (6 inches of ground clearance and 4200 pounds), and i just had it up on jacks since my neighbor PCS'd to Ft.Carson and he took my jack stands with him. well as i was pulling the pipes off the car shifted, fell off the jack and fell down on me. it pinned my left hand onto my chest and i thought i was gonna be a goner, luckily one of my buddies was there and lifted the car at the front wheel enough to take the tension off, allowing me to slide out. i was rushed to ER in an ambulance. after lots of x-rays and cat scans i was released with bruised ribs, bruised scapula, severed nerves in my left hand (they grow back at 2mm per week) and bruised lung. i fully recuperated in about 2 months time and was able to deploy. but i learned a big lesson, if you don't have the proper tools and equipment don't do it, until you get what you need, or take it to a shop.