Lindsay Lohan was determined to stay out of rehab until after the Coachella music festival.

The 'Liz & Dick' actress turned down a string of plea deals ahead of her trial for charges relating to a car crash last June, but finally agreed to spend 90 days in an in-patient facility - in return for pleading no contest to two misdemeanour offences - as she was able to put off the start of treatment until mid-May, meaning she will be able to attend the event next month.

A source told ''Lindsay was adamant that she not be forced to go to rehab until after the Coachella Valley Music and Arts Festival in the Palm Springs area on successive weekends in April. Lindsay loves going to the musical festival, and she's determined to go this year.

''She didn't want a little thing like rehab to get in her way of attending. Lindsay refused to sign off on any deal that would have prevented her from going to Coachella, period. Yes, it's that important to her, for some strange reason.''

It was recently claimed 26-year-old Lindsay - who has attended the event in California for the last three years - will be treated for prescription drug and alcohol abuse when she checks into rehab, but friends are ''doubtful'' whether the treatment will work as the 'Mean Girls' star won't accept she has a problem.

A source said: ''Lindsay will be treated for prescription drug and alcohol addiction during her stay.

''Lindsay's prescription drugs of choice are Adderall and Xanax, and in addition, she consumes large amounts of alcohol - specifically, vodka.

''The main problem when it comes to Lindsay ever getting sober is her absolute denial that she has any substance abuse issues. Of course, there is hope that once Lindsay is undergoing treatment she will recognise that she does in fact have a problem - but given her history, it's very doubtful.''