Built these wooden ramps to accommodate wide tires (old ramps only 9" wide max) and give a 10 inch lift, which allows easy removal of any under body panels for oil changing. E.G. on a Prius. The 1 in 5 slope provides lots of clearance on low bumpers and air deflectors.
The featured Scion XB/Toyota Rukus weighs about 3000 lbs
Ramp build details shown separately.
Video 1   • Car Ramps  part 1  Cutting up the wood  
Video 2    • Car Ramps  part 2 Assembly  

One thing I didn't figure on was that the extra height meant the oil has further to fall during an oil change and if the oil is warm, it's hard to judge where it will land. Fixed that by getting one of those moving dollies from harbor freight and filling the space between the rails with offcuts so it is level. Now I can get the oil into the drain pan again more accurately.