It came as a surprise to the Indian citizens, when in an almost hour long message, Prime Minister last evening declared Rs 500 and 1000 notes as illegal tender. Honest citizens and regular tax payers have nothing to worry about since old notes can either be exchanged at banks and post offices (with a valid ID proof) or can be deposited in accounts.

Here’s how it affect the motorists / Car buyers
Buying petrol/diesel has become difficult
Although it was announced that old notes will remain valid at petrol pumps and they should get accepted. However people are queuing at stations to get tank full in order to get rid of old currency notes.
In any case you do not have the notes, you can use credit cards or options like Petro cards and electronic payment options like PayTM etc. to make payment.
Car buying process
Car buying process is unlikely to remain unaffected, as most payments above a certain limit have to be done with Cheque, DD or Online. Cash payments are generally made as initial down-payment at the time of booking.
If you had been planning to purchase a car, you may not be able to make a down payment in cash.
However, other modes of payment remain valid. In short to mid-term it’s also expected that used car prices are likely to drop.

Hassle at Toll Plaza
Read - SUVs and Luxury Cars will have an Impact by "Currency Scrappage"
If you would check your wallet, you would know that you either have either credit cards / debit cards or notes worth Rs 1000 or 500.
Circulation of Rs 100 notes is quite less in comparison. As a result, it may become difficult to pay at Toll Plazas if you are taking a road trip of travelling between states.
It’s advisable to take cash out of nearest ATM in small denominations of Rs 100, 200, 300, 400 using multiple transactions as it would yield Rs 100 notes which are still valid.

Maintenance / Service
Most people still use cash for getting their cars serviced. However, salaried people can swipe their car and make a payment. People still not familiar with plastic money are more likely to get impacted due to this.
The only alternative is to either wait until you exchange the old notes at banks / post offices. Alternatively use online payment methods that most services stations are likely to support.