In short, no.

There are three aspects to your question, which I’ll separate:

Lobbying I’ve never found any examples of the automakers lobbying specific cities regarding any changes to their streets and roads or local transit, though automakers (or auto company executives) may well have exercised some influence over policies in Detroit. Automakers did use general public relations efforts to promote safer, better intercity highways—notably the newly developed superhighways. GM, for example, presented the hugely influential Futurama exhibit at the 1939 World’s Fair in New York, in which limited-access superhighways were part of both the urban and cross-country future. Ford’s 1956 publication Freedom of the American Road extols the virtues of better, safer highways, and even discusses how cities and suburbs can be served by them, but there’s no disparagement of local transit, which was still an important part of daily life for many Americans.

Streetcars I’ve written before about the “great streetcar conspiracy” and how it’s almost entirely without basis. I’m happy to expand on any parts of that subject people have questions about.

Rapid transit I’ve never come across any allegations of automakers attacking or denigrating elevated and subway rapid transit lines. Elevated rapid transit was certainly seen as an unpleasant disamenity for adjacent residents and businesses, and all the lines in Manhattan were eliminated after WWII, but those in Brooklyn, Queens, Philadelphia, and Chicago were not. The cost of replacement subways were simply too daunting. The spectre of noisy “el” lines blocking sunlight and thundering overhead was prominent in the profound civic distaste for a 1925 plan that would have given Los Angeles a rapid transit network, and sending to defeat a related 1926 proposal to modernize downtown terminals for LA’s interurban and steam railroads.

Mass Motorization + Mass Transit: An American History and Policy Analysis is a good recent scholarly book for those seeking to better understand this topic.

What you're describing is often called the "great streetcar conspiracy". It's been discussed a bit in this sub. A few links:

https://www.reddit.com/r/AskHistorians/comments/kh893p/is_the_gas_rubber_and_car_companies_had_a/ by /u/gothic_sunshine

https://www.reddit.com/r/AskHistorians/comments/tq9fa/whats_the_truth_about_the_great_american/ and https://www.reddit.com/r/AskHistorians/comments/4v6vxv/why_did_virtually_every_us_city_give_up_on_using/d5x8eyg/ by /u/mrdowntown

Basically summation is that GM (not Ford) and other companies maneuvered to monopolize sales of busses, tires, etc to transit agencies. But there were very good reasons why buses replaced streetcars, and streetcar networks contracted significantly or closed entirely even where no conspiracy was involved, and even in cities with public ownership of the network (see esp the first answer by /u/mrdowntown).

But all that is about streetcars, not elevated railways. First of all, as a point of fact, Los Angeles and Washington DC never had Els in the first place. The city with the most famous L is, of course, Chicago. But Chicago never tore down the L. While certain branches were abandoned and demolished, the system remains. Boston tore down several Els--but the Washington St and Charlestown Els were replaced with new alignments (albeit ones that were less convenient for many nearby), and the Causeway St El was replaced with a tunnel. Only the Atlantic Avenue El was truly demolished and removed from service. New York, unusually, did demolish a significant amount of elevated trackage without replacement.

As for the reasons for their demolition, this planning report from 1924 in Massachusetts explains some reasons for the closure, those it wasn't closed till 1938, and wasn't demolished until the scrap metal was needed during WW2. It points out that the route is unprofitable (transit still being privately owned and operated at the time), and interfered with the Washington St Tunnel service (today, the core of the Orange Line). Basically, it was inefficient to have two points on the El where service branched and merged, service could be more frequent by running through the tunnel only (it avoided "reverse branching", for people who've been reading proposals about the NYC subway). The Washington St Tunnel opened a few years after the Atlantic Avenue El, and the El lost a lot of its significance due to other transit expansions.

The report even notes discussion of replacement of all Els in Boston with underground lines. It notes that the chief complaint is noise from elevated railways. It suggests the Atlantic Ave El be converted into an elevated road (not in that form, but later an elevated highway would occupy the same space), and that the Washington St El be replaced with a line adjacent to the NYNH&H railway (which also occurred in the end). But, recommends against replacement of other elevated lines with subways--and we're not talking about demolishing them without replacement here.

New York did close a number of Elevated lines, though quite a number remain. There, though, there was generally an intention to replace them with subways, even though it didn't actually happen (notably the 2nd and 3rd Avenue Els, whose replacement in part has recently opened, several decades later).

Anyway, more to the point, what we're talking about here are systems where Els were replaced with subways, or particular branches that closed. But not the wholesale replacement of elevated systems with buses, the way there was with streetcars. So while the closures may've been due to auto-industry-influenced disinvestment in transit in the mid-1900s, we're not talking about the replacement of an elevated rail system with surface transit the way streetcars were replaced with buses and private cars.