Cleaning product for abandoned car surfaces?

Note this is a many-months-old thread.  Update in last post where a solution was found.  

I recently bought an RX8 that sat outdoors for about 9 years without moving.  As they do sometimes...

Anyway, i am trying to clean it up and all the glass, especially the sunroof,  is coated in a layer of baked on dirt that NOTHING makes a dent in.

I have tried soaking and scrubbing with:

Car wash soap.  Ha!

Simple green at full concentration.  Nope.

K&N heavy duty cleaner spray.  Nope.

Bug and tar remover.   Nada.

Carb cleaner, brakleen, engine degreaser, goo-gone. Hey, why not, they were on the shelf.  No luck.

Plastic razor blade? Nah.

Real razor blade?  Well, that does scrape some off, but that is STILL a struggle that will take hours just for the sunroof at this rate of removal, nevermind the rear window. Plus I am suspicious that the horizontal painted surfaces are equally covered in this crap and I cant razor blade those.

Any suggestions for a more aggressive cleaner?  The paint is bad on the car as the clear coat has failed in large sections, so i am not worried about causing minor paint damage.  However obviously i don't want to dissolve the various plastic and rubber window seals etc.

Can I add , is there a way to remove the dead clear coat  off the whole car without hurting the color coat under it ?

Something that "melts" the clear coat ?

As far as the glass , can you soak a cotton towel in dish soap and let it sit on the glass for an hour or 2 keeping it moist ?

Gel hand sanitizer works on old tree sap it just takes a few minutes of rubbing then it melts.  Maybe worth a try.

Power washer?

Try a claybar?  Instead of the car shop, go to the kids arts and crafts aisle and get bulk...

Dustless blaster?

Okay, it looks like most of the stuff you've used is either solvents (like goo gone) or neutral to high pH cleaners (degreaser.) since none of those have worked, try going the other way. Try some vinegar or lemon juice to see if an acid has any effect. If it seems to have an effect get some acid bathroom cleaner - most grocery or hardware stores will have some version. 
 

the trick to cleaning stuff is trying different extremes until you find the right chemistry. Try a polar solvent (alcohol or hand sanitizer) and a nonpolar solvent (goo gone, kerosene). Try high pH (alkaline, good on grease) or low pH (acid, good on soap scum and water-borne deposits like soap scum and lake scum on boats.)

if the stuff is stupid tough, try soaking a rag in the cleaner and leaving it. But be aware you can damage paint that way too. 

Oh, pressure washer was step 0, no luck.  If you mean like a heated steam cleaner thing, havent tried that yet, don't have one.

Add R3 racing rubber remover to the 'nope' list.

Will try hand sanitizer. Or other alcohol maybe.

Might have a clay bar kicking around sonewhere but oof, my arms are hurting thinking about that.

The car was not under a tree, just in a suburban driveway.  No clue what this stuff is but probably organic? 9 years of pollen etc just caked on?

Likely mineral deposits from rain depending on your location. Mix that with pollen, road dust, etc and it makes a hell of a cement. 

vinegar may have worked a little.  Acetone, laquer thinner, hand sanitizer (gel, 70% ethyl alc) tried on small spots.  Along with the vinegar, these all cut in enough to change the texture of the gunk but not remove or soften it.

Mineral deposit comment made me think maybe a lime-away or calcium buildup remover is the way to go but i don't have anything like that on hand, except straight vinegar.

ultraclyde (Forum Supporter) said:

Okay, it looks like most of the stuff you've used is either solvents (like goo gone) or neutral to high pH cleaners (degreaser.) since none of those have worked, try going the other way. Try some vinegar or lemon juice to see if an acid has any effect. If it seems to have an effect get some acid bathroom cleaner - most grocery or hardware stores will have some version. 
 

the trick to cleaning stuff is trying different extremes until you find the right chemistry. Try a polar solvent (alcohol or hand sanitizer) and a nonpolar solvent (goo gone, kerosene). Try high pH (alkaline, good on grease) or low pH (acid, good on soap scum and water-borne deposits like soap scum and lake scum on boats.)

if the stuff is stupid tough, try soaking a rag in the cleaner and leaving it. But be aware you can damage paint that way too. 

Single best cleaning/surface restoration comment I have seen on here.

brake fluid?

Vinegar "should" work.  Keep a towel soaked with it and let is stay there a while.  

But really, given all that you have tried, I'd switch to fine rubbing compound at this point, and you can use Bon Ami on the glass.  If you truly don't care about the paint, try Comet in a small spot, not on the glass.

We have some drinking glasses that are etched from hard water.  They look just about like your roof glass.  No cleaner will clear them up; they're not coated, the damage is structural / physical. 

Ive had good luck with 409 or awesome and a scotchbrite pad in these situations. Generally,  the paint is buttberkeleyed already,  so i wouldn't plan on even attempting to save it.

Intense heat has worked for me in the past. Have you tried to light it on fire?

How about steel wool, potentially with one of the cleaners along with it.  Finish grade steel wool is what they use to clean it in glass factories. 

One of m fellow drivers uses diluted Clorox.  Swears it works well and doesn't hurt the paint.  I saw her using it a 10-12 year Honda that had been sitting outside for a few years.

RedGT said:

Oh, pressure washer was step 0, no luck.  If you mean like a heated steam cleaner thing, havent tried that yet, don't have one.

I think some of those coin-op DIY car wash places have heated steam/pressure washers that might be worth a shot.

Otherwise... shotgun? :)

68TR250 said:

One of m fellow drivers uses diluted Clorox.  Swears it works well and doesn't hurt the paint.  I saw her using it a 10-12 year Honda that had been sitting outside for a few years.

Bleach + iron = rust.

No ifs ands or buts.

Junkyard digs swears by D Germ from Menards but it might just when he does interiors.

I would definitely try steam.  You can either pick up a small steam cleaner or take it to a place that steam cleans engines.  

Bar keepers friend, if that does not work try comet. 

As always, test in an inconspiculous spot  first.  

Try Using a polisher with a heavy cutting compound after trying some type of clay bar? 
 

My coworker turned this

into this with enough polishing pads anything is possible. Wasn't perfect but was surprising to me.

Baking soda toothpaste on 0000 steel wool. It cleans glass really well. Brass wool world great too on glass surfaces. You can try just a slurry of baking soda and water with the 0000.