These are my notes from Gnomon Basic Drawing in Perspective with Scott Robertson.
An ellipse is simply a circle in perspective:
You can use the same method to extend ellipses as for extending boxes in perspective.
The edges of an ellipse will touch a the edges of a surrounding square that is in perspective. Where these edges meet is the the exact center of each side of the ellipse.
Practise drawing symmetrical ellipses freehand.
Also get accustomed to automatically identifying the minor axis by looking at any given ellipse. The minor axis is the most useful to help draw ellipses in perspective. It cuts each ellipse in perfect half and exhibits symmetry.
A well drawn ellipse can fold along the minor axis onto itself and will be identical on the other side (i.e. is perfectly symmetrical).
Try starting a drawing by just creating guidelines first, then adding in shapes within those guidelines. E.g. start by drawing a grid with squares in perspective. Then, drop shapes in the grid. They will automatically be in perspective.
One of the most important questions to ask before starting a perspective drawing is “what view am I trying to establish”? E.g. am I looking down, up at an object? Is this one, two, three point perspective?
One of the keys to drawing an attractive vehicle is to have a solid foundation for the wheels in perspective.