Connecticut does its resurfacing and sealcoating in the warm months, which is exactly when the material is most mobile. Drive Route 66 or Route 17 through a fresh section and your car will pick some of it up.
Tar is not dirt and it does not behave like dirt.
What happens when it lands
Hot bitumen hits a panel as a liquid droplet. It flows slightly, wetting the surface, and then cools and hardens in place — bonded to the clear coat rather than resting on it.
It lands mostly on the lower third: rocker panels, behind the wheels, the lower doors, and the front bumper. Sometimes higher on the flanks if you were following a truck.
Two things then make it worse over the following weeks. It picks up dust and grit, so each spot becomes a small abrasive lump. And in sunshine it softens and re-flows slightly, spreading and getting further into the paint texture.
The three things not to do
Do not scrub it dry. A hardened tar spot with grit in it, dragged across paint with a cloth, cuts the clear coat. This is the most common way people turn a removable contaminant into permanent damage.
Do not use petrol or an aggressive solvent. They will take the tar off. They will also attack the clear coat and strip any sealant on the panel, and on trim they can leave permanent marks.
Do not leave it all summer. The longer it sits through heat cycles, the more it works into the surface texture and the more aggressive the removal has to be.
What actually works
A dedicated tar remover, which is a mild solvent designed to dissolve bitumen without attacking the paint. It is applied, given time to work — the dwell is the important part, not the pressure — and then lifted away rather than rubbed.
Clay then removes what remains bonded and any residue in the paint texture.
Both are part of our exterior detail at $145 and our full detail at $275. Sealing afterwards matters here more than usual, because a solvent step removes whatever protection was on the panel and it needs replacing.
The bit under the arches
Tar also collects inside the wheel arches and on the arch liners, where nobody looks, and it holds grit against the metal in the same way packed sand does.
That is worth dealing with in the same visit rather than separately, and it is part of why a proper exterior job takes longer than a wash.
If it has already etched
Occasionally a spot that has sat all summer leaves a mark after the tar itself is gone — a dulled patch where the surface texture has changed. That is machine polish work rather than chemical, which is paint correction at $449.
That is uncommon and we would rather tell you it is not needed. Most tar, removed properly, leaves nothing at all behind.