Insulating a Garage Door - Cheapest Ideas?

I have two one-car garage doors on my house that are sucking away the heat from the house. Especially the master bathroom above it. I was wondering about your solutions to insulating it. You can buy many kits, but they all seam lacking in one or two details. Mostly dimensions large enough, thick enough, or lacking any form of clean appearance.

The dimensions of my garage doors are 9’x7’ with 21”x50”x2” sections (8 sections/door) and are metal panels. Most of the kits come with either 48” wide panels or those that are long enough are only 20” or less in height and in many cases less than 1.5” thick. Also, they do not leave a very finished appearance. The Reflectix material looks ugly and detracts from a finished garage (well, the drywall is up, not painted yet). My idea is to purchase 4 – 4’x8’ sheets of 2” thick insulfoam and cut it to size. However this causes some problems, the only way to get 50” is to cut them along the long axis and then I can only get 2 panel sections. Since I need 16 sections, and at $25 a pop, that would be over $200. I think I can do it for just over a $100.

Here is my idea. I cut 4 sections that are 21” x 48”. I have to dado the bottom and top edges to match the groves in the metal panels. I’ll use my router table for that.

To get the 50” width. I’m going to have 1’x4’ left at the top of the panels as scrap. I take those sections and cut them into 4 – 4” x 21” sections and I’ll dado a 2” wide lip to overlap the 48” panel which will have a matching dado.

My panels also have 3/8” insets for the raised panel look of the doors. I’ll have to reduce the thickness of the Insulfoam by 3/8” using my router and a jig to hold it at the proper height.

Now how do I get the panels in the sections? Well, the sections are 21” in height, however, the metal lip takes away almost a full inch. So I’m thinking of using the table saw and cutting several relief groves in the foam to allow it to flex enough to insert it into the garage door.

I’ll secure the foam using a common bonding caulking such as liquid nails.

Now for the surface? My thought is to primer and paint the exposed surface to match the color of the garage doors. This should make it look very professional and clean.

Overall, does this sound feasible? I know it is alot of work, but it should look nice and provide almost R-8 insulation value to the doors.