Are you ignoring the circular nature of the wheel? The distance will be different at different points.
Alignment machines take the guesswork out by finding the center of the hubs and projecting laser beams.

 

I measure from the bolt head with a socket over it to the centre of the tread , there was still the mold line on it .

 

And you are absolutely sure that you are hitting both tires at exactly the same relative point on the radius of the tire; and that both tires have exactly the same amount of wear.
But the +-0.20 degree is fairly sloppy.

 

I’m confident in my measurements are close, the car drives straight, doesn’t pull when braking.

 

(Had to read that twice or thrice to decode what you were getting at. Ya snark. Circular nature of a wheel? Who knew? I kinda that I covered that in #10, but I edited the last sentence for clarity.)

Oh, I'm not pretending any improvising technique is a good as the dedicated equipment, but with a modicum of car, more than good enough.

Yes, +0.20° ±0.20° is pretty forgiving. Which is why it's do-it-yerseffible. Even a bit of room to customize to your performance properties preferences and predilections. I find if a car with everything tight tends to wander, it might benefit from moving closer to the max toe-in limit. (Not hardly an expert, but did my 1st suspension tweeking in 1973 on my 1966 Corvair Corsa. You wanna talk about interesting handling properties...)

 

I learned front end alignment techniques with one of these bars back in the late sixties 1/8 inch total toe was pretty much standard on cars then

These plates are easy to use to get close enough to perfect

You measure and adjust with the wheels off the car, I would put the jack stand under the suspension to compress the springs, in this photo they are working on a Jeep but still appears to be IFS They use these plates in NASCAR and I would use these on my Dirt modified cars

 

that I would trust to be reasonably accurate, better than using the tire tread. could even get by with a homemade version I bet

 

Curious if there is an easy way to get it almost perfect until the new outer tie rod ends come in.

I grabbed a level and put it at the middle of the wheel. It hits the back of the wheel well first, top is higher before it hits.

also, would the rear wheels be any indication as well? The front seems pointed in too far (toe in) compared to the rear.

 

The HHR has the same wheel track width front and back. So, just adjust the outer edge of the front tires to line up with the outer edge of the back tires. LF to LR. RF to RR.
Back in my mechanic days we used this “ by sight “ method after any repair work that messed with the toe. Using “ by sight” would get it pretty close to a 0 degree setting.
Note: make sure the steering wheel is locked centered before doing any adjustments.

 

I did it by sight and it's riding pretty nice. I still get some very slight pulling when driving over some bumps/uneven pavement, but nothing like before.

I got it up to 60 on an empty back road (50mph limit) and there was no wobble at all. Also none when braking. Before it would wobble noticeably at 45-70. Going to hit the freeway for a beer run and see how it does at higher speeds.

I still get a hollow clunk once in a while, not sure what that is. I already swapped the upper strut mounts. Maybe time for new shocks up front.

Hopefully the new outter tie rod ends do something to help too. I ordered the green and beige mevotechs for $70/pair shipped.

I did notice a "power steering" message on the display after installing the rack. Not sure if I bumped something while messing with the inside steering shaft bolt or if the car detected it somehow. Also got "service esc" and "esc off" But I do hear a front wheel bearing so I'm gonna swap that. (Will LT work on SS? I still have one on the shelf)