Stealth depend a lot on the layout on your windscreen, some have unreasonable large sensor arrays drooping down on the glass right where its the best place to put a camera.
My favorite are the glass hugging wedge shaped cameras, as even on a plain old windscreen or mounted offset to some sensors, the camera can often come off as a factory sensor of some sort.
you can get ideas to install by browsing the where did you install your dashcam picture thread.
3D wedges repositioned for side-by-side Mobius testing:
dashcamtalk.com
Convertibles are notoriously problematic when it come to 2 channel systems, the best option i think is that some brands do provide a option for a waterproof camera you could mount way out back.
There are also the taxi / uber 2 in one cameras, but as the rear camera are on the windscreen looking out back the 2 front seats and passengers in those can block a lot of the view.
These 2 in one camera are also often not of the most stealthy design, so not something i would consider if you like to be a little stealthy, the rear camera are mainly meant to film passengers in the car for identification purpose in case they do something nasty.
A third camera is also a bit of a challenge, the systems are sort of there ( 3 and 4 channel ) but they are still very immature, and the few side mounted options there are are all meant for looking strait out back and not so much down other than what the field of view provide.
What about good old school analog curb feelers ?
en.wikipedia.org
Some cameras still have AV out, but no automated switching like you see on cars with a reversing camera, but some have wifi too but there is always a little lag, just 0.5 second or so which should not be a problem at parking speeds.
But again not really any down facing cameras, and so you have to mount a camera looking back along the side way out front, but that will be a challenge to do and also install, you would probably have to drill a hole in that pony car.
I am not a fan of low profile tires and big diameter wheels, i call it euro trash boy racer wheels, guess im just too old for that stuff, plus i have a big urge to be different and so many do low profile tires and big wheels.
I would even like to have my one +30 years old tattoo removed as now, kids and grandmothers do tattoos, when i got mine only sailors / bikers and criminals had tattoos, and i was a criminal then and a little later sailor too when i cast aside my evil ways.
Thinkware have a 4 channel system with side cameras in the pipeline, but intended install just in front of front door gap on the front fender so do not cover the front wheel, but i assume you could mount it out ahead of the front wheel, but not sure how good a shot down the side to the rear wheel it would give you.
S Korean G-net also make a side camera setuo ( 2 channel ) but it is only 720p, which by all means are fine for navigating a curb, but the fov are not large and to see both wheels you will either have to mount camera as far as you can and still be able to film down the side, or mount both cameras on the same side, with one out back looking forward, but that is a weird solution i think.
A DIY solution might be to get a spare wing mirror from a salvage yard ( i assume plenty have managed to ruin their nice pony car ) then install a camera in it facing strait down, and with a very wide lens, but this will mean you have a lot of fish eye in the footage, and somehow you will have to figure out a way yourself to waterproof the exposed lens and the camera body inside the mirror housing.
And then have it painted in your cars colors.
But a such wide angle lens also distort the image, so with no post processing in the camera the side of your car would look like a banana and it would probably take some getting used to.