I do the Trans Am with waxoil in a paraffin gun on my compressor, thinned down about 50%(ish) with white spirit. I mix it, then filter it through some stockinette into a big jam jar to remove any lumps as they will block the gun.
Works a treat, probably not as good as neat waxoil, but at least it gets everywhere. I tend to do it each year so I get a cumulative effect.
Wear a facemask if doing it in a garage as it makes a lot of vapour.
I also found it's better to buy the black waxoil as I can see where I've put it on the underneath as my car is gold and the yellow stuff doesn't show up well.