I can't comment about Pakwheels not welcoming Indians bragging about their goods. Unless ofcourse there's such a rule. In thats case perhaps the mods should bar Indians from joining.
On outdated Indian cars in movies:
Before 1990, India practised a closed door policy. No foreigner could invest without majority indian participation and a list of formalities (which includes "you know what"). Hence, local car makers were sleeping and producing some trash like Padminis because they knew that they were monopolists. No one could offer cars better than their 30 years outdated cars. Once India began opening up their economy in the 90s, there was a sea of foreign investment. Koreans, Japs etc stormed the market with their better products, and obviously they ended Padminis monopoly (and existance!). This competition brought about better living standards to people. There's no denying on India's economic growth story since the 90s. Same case for China (opened in the 80s) and Russia (effective after Putin came in). We can all see how well those two countries have progressed since opening up. India's founding fathers thought "non dependence on the outside world" was the key to progress, but it was proven wrong and turned around by their future generations.
In Pakistan it isn't as bad. Foreign investment is allowed ex from India. Jap and Chinese bike makers there are having a good time sleeping because they know there's no competition. They are not gonna initiate new products because for that they need capital + risk. Capital for advertising, retraining workers, new machinery etc. Investing in a new product is risky as there's no confirmation how market would react. Moreover it would take time for their investment to pay off (perhaps after selling say, 2000 units). So to cut the problems short: while their current range is unmatched, they won't take any risks. No businessman would take an unnecessary risk. In other markets, initiating new products is a necessary risk for survival.
I understand Pakistanis sentiments, fearing Indian goods would dominate their market. But if you notice, Indian companies like Bajaj, TVS, Mahindra etc only became as competitive as they are today producing better cars after India opened its doors. Same goes with Chinese car companies. Perhaps in the next 5 years if Indian bikes enter Pakistan they may dominate, but market forces WON'T let that prevail in the long term.
Indians expected the demise of their home industries after opening up. But today their home companies are stronger than ever. Compare in Indian cars/bikes pre-1990 and post-1990. Compare the strength of those companies pre and post 1990. I don't need to explain further. We hear them gobbling up large, billion dollar western companies. Something unheard of just 2 decades back.
I like Indo-China ties in that respect. Although political relations between India and China are as bad (if not worse) than Indo-Pak relations, they don't mix trade with politics and proceed ahead where they can. Chinese are wooing Indian IT companies to China, while Indians are wooing Chinese to invest in infrastructure.
On why Indian cars aren't as hot as their Jap counterparts, there's no denying that Indian cars are no match compared to Jap / Korean. But does that mean since Tata sells better than Toyota in India, Tata is better? Or Mahindra sells better than Mitsubishi. Does it mean Mahindra better? Bajaj sells more than Kawasaki. It means Bajaj better? What those Indian companies seek is an open market to compete fairly and let the market forces determine their quality. Why should we fight on quality. Let their markets decide. Those Indian brands will keep fighting as long as they can make a good profit, something they've been doing amidst better East Asian and continental cars.
But what I clearly can see is Indian products would be a hit in Pakistan and that's why Pakistanis are scared to allow them in. If so confident it won't sell, why fear? Why talk about "dominating the market" if they feel it won't sell?