Yeah, or I'd just drive it warm, and get a can of air duster invert it and hit just the bolt with it (comes out as liquid like freeze spray, or you can get real freeze spray of course)

Another idea for the stubborn nut: Nut splitter.
$10 at Harbor Freight.
https://www.harborfreight.com/cpi/pho...8899/98801.gif

You can get a security bit set with those and other types for $5-20 on eBay or Harbor Freight.
https://www.harborfreight.com/cpi/cta...emnumber=93388
https://www.harborfreight.com/cpi/cta...emnumber=91310
https://search.ebay.com/search/search...ecurity+bit%22

I didn't know about Harbor Freight at the time... I saw a set at Sears for something like $25, but that is a ton of money for a 5-piece bit set. Cutoff discs are cheap. Besides, most of the security torx things are pretty normal screws, so if you can get them out once, you can replace them w/philips...

I no longer own the VW, and haven't run into any security torx since then. The could very well be all over the Hyundai, for all I know, but that car is still low milage & under warranty, so only the dealer has really touched it. That'll change soon. I want to try a WAI on it. It may not be easy, because a 5 minute search under the hood did not reveal the location of the intake--you can't see any part of the bottom of the air filter box w/o removing something.

Take a piece of flat bar, cut a hole in it to match the shape of your buggered head, and mig weld the bar to the nut. Whack it a couple of times with a hammer until it starts to move.

Grind or file the head until you can get a smaller 6 sided socket on the nut, use another nut for your pattern. If you can get it close drive the socket on the nut. Then use a breaker bar.

I have used the weight of the car to get enough pressure on a breaker bar to break an axle nut loose. The three foot breaker bar bent almost 9 inches before it finally let go.

Heat the area around the plug and then hold pieces of ice on the plug to use expansion and contraction .

regards
gary

I have a set of sockets that I bought at Sears that are designed just for removing rounded bolts. There are about 5 different sized sockets in the SAE set and about 5 different sizes in the metric set. They have a spiral inside which is supposed to grip the rounded bolt. I have had them for a couple of years, but have never had to use them so I don't know how well they work. I have also saw people use an air chisel near the corner of the flats to knock rounded bolts loose. I'm not sure this is something you would want to try around the aluminum.

i have used these...https://www.bt-andf.com/products.php 'cause i don't have a way to use heat, and 'cause the nut/bolt can be reused. they're a bit expensive tho. of course, they're for rounded nuts/bolts, so if the original issue of torque and space is limited well...