I need help drawing in 3D, please!

[The Creative Explorer]

I've been using Autodesk Inventor for a while now and with the basic things, I am doing well. I was going to take it a step further and tried drawing a frontbumper and a tailgate for the 911, but whatever I do, I can not find anything to work with me with the complex curves.

I've wasted 2 full days on it now and I am at the point of tossing the computer.

 

Is there anybody willing to help me out by guiding me? I would be very appreciative.

[Ace-Garageguy]

One of the Autodesk "help" pages has this to say:

"The Intersection Curve tool creates 3D sketch curves from intersecting geometry. You can use it to create shapes used in consumer products, piping, and to control the shape of complex lofts."

https://knowledge.autodesk.com/support/inventor-products/learn-explore/caas/CloudHelp/cloudhelp/2016/ENU/Inventor-Help/files/GUID-37BA1DCE-6BC4-41CD-A36D-577F31B304FC-htm.html

[Spex84]

I don't know Autodesk Inventor, but I assume it's CAD-like (parametric modeling, NURBS, etc). 

In general, I suggest breaking it down into manageable chunks.  The bulk of a stock 911 bumper could probably be made with a Loft  operation or Sweep 2 rails (or whatever the equivalent is with your software); anything that builds a 3D surface by smoothly building a surface across a series of cross-section curves, with the edges guided by a second pair of curves.

Put a blueprint or non-distorted photo on a flat plane in the viewport to act as a guide if possible. 
Draw out all the curves as if making a wire-mesh of the part, and those curves will help immensely when defining surfaces. 

Just about any car design has more complicated things going on with it than most people would initially notice. 

 Sharing a photo or drawing of what you're trying to create might help too!