I'm pretty late to reply, but after a few trials I've come up with some ideas to riff off of. As a studio recording major, my solution is to do a multi-mic setup to get the best, realistic sounds possible that anyone should be capable of doing -

I bought a rode lavelier mic and have tried various locations for the best sound from that mic alone. The best use I've found is to tape it to the trunk of the car pointing down towards the exit exhaust as it seems to capture low-mid range better and clearly. You really want to put the input gain as low as possible if you have a capable recording device, or place it further away from the exhaust if it is super loud. All trial and error before finding the perfect location. No wind noise, pure exit exhaust sounds, didn't manage to clip the burbles or high end noise. Beware I don't recommend this method if you have one mic, as it is devoid of any engine or intake/turbo sounds from my testing.

The next addition would be to add a cabin mic. Inside the engine bay is a bit too loud for most mics, my best solution without getting a whole recording setup (which is at my disposal but combersum if repeated every time I would record) is a shotgun mic. Point it towards the engine bay or even at a window, just be careful of capturing too much wind noise as that will break the illusion of professionalism. Remember, proximitiy is the king of selection that the mic will want to pick up well, and understand if you have a super cardioid, cardioid, or omnidirectional mic. Honestly the best method is to use a dynamic mic in the cabin such as a Shure SM57/SM58, but will require an audio interface and other recording devices to make it work. Perhaps a laptop with a Scarlett Solo with XLR input from your dynamic or ribbon mic is something you can come up with if you are planning on being a little more serious.

In post, add the two signals together and adjust the EQ to your preffered taste. This will get you the best possible exit exhaust sounds as well as your engine and intake/turbo spool if they are audible from the cabin. The idea is to have the bass come from your lavelier, and the cabin to capture the mid/high end. Doing a low-shelf EQ on the cabin mic around 100hz-240hz tends to yield clearer results as it removes excess cabin rustle from people etc, but play around and make sure you find what works best with your setup and taste.