I've got the Hague headrest strut mount which works flawlessly, has done for 15 years now, but as the seat moves a little when you're hammering it on track you ideally need something with some inbuilt stabilisation to compensate for that movement.
For an alternative, and without needing to buy a suction mount, consider using one of the flat sticky mounts on your windscreen. I use it to have the camera facing inwards but you could easily have it facing forwards as well. You will probably need a tether as well for that one...I use para cord ones which are available on eBay/Amazon for actual pennies. As it's a fixed rigid mount you need zero stabilisation.
Also, if you can, get hold of one of the swivel ball mounts I'm using in the picture above. I think GoPro have discontinued them now so I tend to buy them whenever they come up for <£20 - it completely removes the old two axis only alignment issues you might have and blows away every other swivel/ball type mount I've tried...and I've tried a few!
Mounted low on the front bumper for a change. Depends what you want to see I guess.
View attachment 1423720
Perfect if the track you're on is happy with tethered external cameras, I love that low shot!
This is the ONLY way I've found to capture the true gradient and elevation changes on camera